SOLUTION: Considering \[x\text{ }+\text{ }y\text{ }=\text{ }8,\] The shaded region and the origin both are on the same side of the graph of the line and (0, 0) satisfy the constraint \[x\text{...
Find the linear inequalities for which the shaded region in the given figure is the solution set.
SOLUTION: According to the question, Considering \[3x\text{ }+\text{ }2y\text{ }=\text{ }48,\] The shaded region and the origin both are on the same side of the graph of the line and (0, 0) satisfy...
Solve the following system of inequalities
Solution: For above fraction be greater than 0, either both denominator and numerator should be greater than 0 or both should be less than 0. \[\begin{array}{*{35}{l}} \Rightarrow ~6\text{ }\text{...
In drilling world’s deepest hole it was found that the temperature T in degree Celsius, x km below the earth’s surface was given by T = 30 + 25 (x – 3), 3 ≤ x ≤ 15. At what depth will the temperature be between 155°C and 205°C?
\[T\text{ }=\text{ }30\text{ }+\text{ }25\left( x\text{ }\text{ }3 \right),\text{ }3\text{ }\le \text{ }x\text{ }\le \text{ }15;\] where, T = temperature and x = depth inside the earth The...
The longest side of a triangle is twice the shortest side and the third side is 2 cm longer than the shortest side. If the perimeter of the triangle is more than 166 cm then find the minimum length of the shortest side.
Let the length of shortest side = ‘x’ cm According to the question, The longest side of a triangle is twice the shortest side ⇒ Length of largest side = 2x Also, the third side is 2 cm longer than...
A solution is to be kept between 40°C and 45°C. What is the range of temperature in degree Fahrenheit, if the conversion formula is F = 9/5 C + 32?
Let temperature in Celsius be C Let temperature in Fahrenheit be F According to the question, Solution should be kept between 40° C and 45°C ⇒ 40 < C < 45 Multiplying each term by 9/5, we get...
A solution of 9% acid is to be diluted by adding 3% acid solution to it. The resulting mixture is to be more than 5% but less than 7% acid. If there is 460 litres of the 9% solution, how many litres of 3% solution will have to be added?
According to the question, Let x litres of 3% solution is to be added to 460 liters of the 9% of solution Then, we get, Total solution = \[\left( 460\text{ }+\text{ }x \right)\text{ }litres\] Total...
The water acidity in a pool is considered normal when the average pH reading of three daily measurements is between 8.2 and 8.5. If the first two pH readings are 8.48 and 8.35, find the range of pH value for the third reading that will result in the acidity level being normal.
According to the question, First reading = 8.48 Second reading = 8.35 Now, let the third reading be ‘x’ Average pH should be between 8.2 and 8.5 Average \[pH~=\text{ }\left( 8.48\text{ }+\text{...
Since, Profit = Revenue – cost Requirement is, profit > 0 \[C\left( x \right)\text{ }=\text{ }26,000\text{ }+\text{ }30\text{ }x;\] where x is number of cassettes \[\begin{array}{*{35}{l}}...
Solve for x, the inequalities in 4x + 3 ≥ 2x + 17, 3x – 5 < – 2.
\[\begin{array}{*{35}{l}} 4x\text{ }+\text{ }3\text{ }\ge \text{ }2x\text{ }+\text{ }17 \\ \Rightarrow ~4x\text{ }\text{ }-2x\text{ }\ge \text{ }17\text{ }\text{ }-3 \\ \Rightarrow ~2x\text{ }\ge...
Solve for x, the inequalities in
Solution: Multiplying each term by 4, we get \[\Rightarrow ~-20\text{ }\le \text{ }2\text{ }\text{ }-3x\text{ }\le \text{ }36\] Adding -2 each term, we get \[\Rightarrow ~-22\text{ }\le \text{...
Solve for x, the inequalities in |x – 1| ≤ 5, |x| ≥ 2
\[\left| x\text{ }\text{ }-1 \right|\le \text{ }5\] There are two cases, 1:-\[x\text{ }\text{ }-1\text{ }\le \text{ }5\] Adding 1 to LHS and RHS \[\begin{array}{*{35}{l}} \Rightarrow ~x\text{ }\le...
Solve for x, the inequalities in
Solution: \[\begin{array}{*{35}{l}} \Rightarrow ~5-\text{ }\text{ }\left| x \right|\text{ }\le \text{ }0\text{ }and\text{ }\left| x \right|\text{ }\text{ }-3\text{ }>\text{ }0\text{ }or\text{...
Solve for x, the inequalities in
Solution: Hence, \[\begin{array}{*{35}{l}} 1\text{ }\le \text{ }y\text{ }<\text{ }2 \\ \Rightarrow ~1\text{ }\le \text{ }\left| x-\text{ }\text{ }2 \right|\text{ }<\text{ }2 \\ \end{array}\]...
Solve for x, the inequalities in
SOLUTION: Multiplying each term by \[\begin{array}{*{35}{l}} \left( x\text{ }+\text{ }1 \right) \\ \Rightarrow ~4\text{ }\le \text{ }3\left( x\text{ }+\text{ }1 \right)\text{ }\le \text{ }6 \\...
If z and w are two complex numbers such that |zw| = 1 and arg (z) – arg (w) = π/2, then show that z̅w = – i.
Let z = \[\left| z \right|\text{ }(cos\text{ }{{\theta }_{1}}~+\text{ }I\text{ }sin\text{ }{{\theta }_{1}})\text{ }and\text{ }w\text{ }=\text{ }\left| w \right|\text{ }(cos\text{ }{{\theta...
Write the complex number in polar from.
SOLUTION:
Find the complex number satisfying the equation z + √2 |(z + 1)| + i = 0.
\[z\text{ }+\text{ }\surd 2\text{ }\left| \left( z\text{ }+\text{ }1 \right) \right|\text{ }+\text{ }i\text{ }=\text{ }0\text{ }\ldots \text{ }\left( 1 \right)\] Substituting\[z\text{ }=\text{...
Solve the system of equations Re (z2) = 0, |z| = 2.
\[\begin{array}{*{35}{l}} Re\text{ }({{z}^{2}})\text{ }=\text{ }0,\text{ }\left| z \right|\text{ }=\text{ }2 \\ Let\text{ }z\text{ }=\text{ }x\text{ }+\text{ }iy. \\ Then,\text{ }\left| z...
If for complex numbers z1 and z2, arg (z1) – arg (z2) = 0, then show that |z1 – z2| = |z1| – |z2|.
Let \[{{z}_{1}}~=\text{ }\left| {{z}_{1}} \right|\text{ }\left( cos\text{ }{{\theta }_{1}}~+\text{ }I\text{ }sin\text{ }{{\theta }_{1}} \right)\text{ }and\text{ }{{z}_{2}}~=\text{ }\left| {{z}_{2}}...
If |z1| = |z2| = ….. = |zn| = 1, then show that |z1 + z2 + z3 + …. + zn| = | 1/z1 + 1/z2 + 1/z3 + … + 1/zn|
\[\begin{array}{*{35}{l}} \left| {{z}_{1}} \right|\text{ }=\text{ }\left| {{z}_{2}} \right|\text{ }=\text{ }\ldots \text{ }=\text{ }\left| {{z}_{n}} \right|\text{ }=\text{ }1 \\ \Rightarrow...
If z1, z2 and z3, z4 are two pairs of conjugate complex numbers, then find arg(z1/z4) + arg(z2/z3).
z1 and z2 are conjugate complex numbers. The negative side of the real axis \[\begin{array}{*{35}{l}} =\text{ }{{r}_{1}}~\left( cos\text{ }{{\theta }_{1}}~\text{ }-i\text{ }sin\text{ }{{\theta...
If |z1| = 1 (z1 ≠ –1) and z2 = (z1 – 1) / (z + 1), then show that the real part of z2 is zero.
Let z1 = x + iy Therefore, the real part of z2 is zero.
z1 and z2 are two complex numbers such that |z1| = |z2| and arg (z1) + arg (z2) = π, then show that z1 = – z̅2.
According to the question, Let \[{{z}_{1}}~=\text{ }|{{z}_{1}}|\text{ }(cos\text{ }{{\theta }_{1}}~+\text{ }I\text{ }sin\text{ }{{\theta }_{1}})\text{ }and\text{ }{{z}_{2}}~=\text{...
If (z – 1)/(z + 1) is a purely imaginary number (z ≠ –1), then find the value of |z|.
\[Let\text{ }z\text{ }=\text{ }x\text{ }+\text{ }iy\] Now, \[\begin{array}{*{35}{l}} \Rightarrow ~{{x}^{2}}~\text{ }-1\text{ }+\text{ }{{y}^{2}}~=\text{ }0 \\ \Rightarrow ~{{x}^{2}}~+\text{...
Show that |(z – 2) / (z – 3)| = 2 represents a circle. Find its centre and radius.
\[\begin{array}{*{35}{l}} arg(\left| \left( z\text{ }\text{ }-2 \right)\text{ }/\text{ }\left( z-\text{ }\text{ }3 \right) \right|\text{ })=\text{ }2 \\ Substituting\text{ }z\text{ }=\text{...
If arg (z – 1) = arg (z + 3i), then find x – 1 : y. where z = x + iy
Let \[z\text{ }=\text{ }x\text{ }+\text{ }iy\] Given that, \[arg\text{ }\left( z-\text{ }\text{ }1 \right)\text{ }=\text{ }arg\text{ }\left( z\text{ }+\text{ }3i \right)\] \[\Rightarrow ~arg\text{...
If |z + 1| = z + 2 (1 + i), then find z.
\[\left| z\text{ }+\text{ }1 \right|\text{ }=\text{ }z\text{ }+\text{ }2\text{ }\left( 1\text{ }+\text{ }i \right)\] Substituting z = x + iy, we get, \[\Rightarrow ~\left| x\text{ }+\text{ }iy\text{...
Solve that equation |z| = z + 1 + 2i.
As per the inquiry, We have, \[\left| z \right|\text{ }=\text{ }z\text{ }+\text{ }1\text{ }+\text{ }2i\] Subbing z = x + iy, we get, \[\begin{array}{*{35}{l}} \Rightarrow \left| x\text{ }+\text{ }iy...
Show that the complex number z, satisfying the condition arg ((z-1)/(z+1)) = π/4 lies on a circle.
Let \[z\text{ }=\text{ }x\text{ }+\text{ }iy\] arg \[\left( \left( z-1 \right)/\left( z+1 \right) \right)\text{ }=\text{ }\pi /4\] \[\Rightarrow ~arg\text{ }\left( z\text{ }\text{ }1 \right)\text{...
If the real part of ( z̅ + 2)/ ( z̅ – 1) is 4, then show that the locus of the point representing z in the complex plane is a circle.
Let z = x + iy Now, \[\Rightarrow ~{{x}^{2}}~+\text{ }x\text{ }\text{ }-2\text{ }+\text{ }{{y}^{2}}~=\text{ }4\text{ }\left( {{x}^{2}}~\text{ }-2x\text{ }+\text{ }1\text{ }+\text{ }{{y}^{2}}...
If z = x + iy, then show that zz̅ + 2(z + z̅) + b = 0 where bϵR, representing z in the complex plane is a circle.
\[z\text{ }=\text{ }x\text{ }+\text{ }iy\] ⇒ z̅ = x – iy Now, we also have, z z̅ + 2 (z + z̅) + b = 0 \[\Rightarrow ~\left( x\text{ }+\text{ }iy \right)\text{ }\left( x\text{ }\text{ }iy...
If (1 + i)z = (1 – i) z̅, then show that z = i z̅.
SOLUTION: = -iz̅ Hence proved.
If a = cos θ + i sin θ, find the value of
SOLUTION: a = cos θ + i sin θ
IF
then find (a, b). Solution: = (i4)25 = 1 Hence, (a, b) = (1, 0)
If (FIG 1) then find the value of x + y.
FIG 1: SOLUTION: We have,
If (fig 1), then find (x, y).
fig 1: SOLUTION: We have,
For a positive integer n, find the value of (1 – i)^n (1 – 1/i)^n.
A/Q = (1 – i)n (1 + i)n = (1 – i2)n = 2n Therefore, (1 – i)n (1 – 1/i)n = 2n
Prove n^2 < 2n for all natural numbers n ≥ 5.
As indicated by the inquiry, \[P\left( n \right)\text{ }is\text{ }n\hat{\ }^2\text{ }<\text{ }2n\text{ }for\text{ }n\ge 5\] Let \[P\left( k \right)\text{ }=\text{ }k^2\text{ }<\text{ }2k\] be...
Prove 3^2n – 1 is divisible by 8, for all natural numbers n.
As indicated by the inquiry, \[P\left( n \right)\text{ }=\text{ }32n\text{ }\text{ }1\] is distinct by 8. Along these lines, subbing various qualities for n, we get, \[P\left( 0 \right)\text{...
Prove 2^3n – 1 is divisible by7, for all natural numbers n.
As indicated by the inquiry, \[P\left( n \right)\text{ }=\text{ }23n\text{ }\text{ }1\] is detachable by 7. In this way, subbing various qualities for n, we get, \[P\left( 0 \right)\text{ }=\text{...
Give an example of a statement P(n) which is true for all n. Justify your answer.
As indicated by the inquiry, P(n) which is valid for all n. Let P(n) be, ⇒ P(k) is valid for all k. In this manner, P(n) is valid for all n.
Give an example of a statement P(n) which is true for all n ≥ 4 but P(1), P(2) and P(3) are not true. Justify your answer.
As indicated by the inquiry, P(n) which is valid for all n ≥ 4 however P(1), P(2) and P(3) are false Let \[P\left( n \right)\text{ }be\text{ }2n\text{ }<\text{ }n!\] Thus, the instances of the...
On a square cardboard sheet of area
, four congruent circular plates of maximum size are placed such that each circular plate touches the other two plates and each side of the square sheet is tangent to two circular plates. Find the area of the square sheet not covered by the circular plates.
Given Area of the square = \[784\] \[c{{m}^{2}}\] Hence Side of the square = \[\sqrt{Area}\] = \[\sqrt{784}\] = \[28\] cm Given that the four circular plates are congruent, Therefore diameter of...
Four circular cardboard pieces of radii
cm are placed on a paper in such a way that each piece touches other two pieces. Find the area of the portion enclosed between these pieces.
solution From the given information, it is given that the four circles are placed such that each piece touches the other two pieces. Now by joining the centers of the circles by a line segment, we...
Find the area of the sector of a circle of radius
cm, if the corresponding arc length is
cm.
solution Given Radius of the circle = r = \[5\] cm Given Arc length of the sector = l = \[3.5\] cm Let us consider the central angle (in radians) be \[\theta \]. As we know that Arc length = Radius...
Three circles each of radius
cm are drawn in such a way that each of them touches the other two. Find the area enclosed between these circles.
Solution: Given that the three circles are drawn such that each of them touches the other two. Now, by joining the centers of the three circles, We get, AB = BC = CA = \[2\] (radius) = \[7\] cm...
In Fig. 11.17, ABCD is a trapezium with AB || DC, AB =
cm, DC =
cm and distance between AB and DC =
cm. If arcs of equal radii
cm with centres A, B, C and D have been drawn, then find the area of the shaded region of the figure.
Solution Given AB = \[18\] cm, DC = \[32\] cm Given, Distance between AB and DC = Height = \[14\] cm We know that Area of the trapezium = (\[1/2\]) × (Sum of parallel sides) × Height =...
A circular pond is
m is of diameter. It is surrounded by a
m wide path. Find the cost of constructing the path at the rate of Rs
per
Solution: Given Diameter of the circular pond = \[17.5\] m Let us consider r be the radius of the park = \[(17.5/2)\] m = \[8.75\] m Given The circular pond is surrounded by a path of width \[2\] m....
Which of the following are sets? Justify our answer. (i) A team of eleven best-cricket batsmen of the world. (ii) The collection of all boys in your class.
Solution: (i) A group of eleven of the world's best cricket batsmen is not a well-defined collection. Because the criteria used to determine a batsman's talent differ from person to person. As a...
Find the area of the segment of a circle of radius
m whose corresponding sector has a central angle of
(Use
).
Solution: From the given information, Radius of the circle = r = \[12\] cm ∴ OA = OB = \[12\] cm \[\angle AOB={{60}^{\circ }}\] (given) As triangle OAB is an isosceles triangle, ∴ \[\angle...
Find the area of the segment of a circle of radius
m whose corresponding sector has a central angle of
(Use
).
Solution: From the given information, Radius of the circle = r = \[12\] cm ∴ OA = OB = \[12\] cm \[\angle AOB={{60}^{\circ }}\] (given) As triangle OAB is an isosceles triangle, ∴ \[\angle...
Sides of a triangular field are
m,
m and
m. With the three corners of the field a cow, a buffalo and a horse are tied separately with ropes of length
m each to graze in the field. Find the area of the field which cannot be grazed by the three animals.
Solution From the given question, We got Sides of the triangle are \[15\] m, \[16\] m and \[17\] m. Then, perimeter of the triangle = \[(15+16+17)\] m = \[48\]m Therefore, Semi-perimeter of the...
The diameters of front and rear wheels of a tractor are
cm and
m respectively. Find the number of revolutions that rear wheel will make in covering a distance in which the front wheel makes
revolutions.
solution From the given question, We got, Diameter of front wheels = \[{{d}_{1}}\]= \[80\] cm we got, Diameter of rear wheels = \[{{d}_{2}}\]= \[2\]m = \[200\] cm Let us consider \[{{r}_{1}}\] be...
The area of a circular playground is
. Find the cost of fencing this ground at the rate of Rs
per metre.
From the given question, We got Area of the circular playground = \[22176\] \[{{m}^{2}}\] Let us consider r as the radius of the circle. Therefore, \[\pi {{r}^{2}}=22176\]...
In Fig. 11.7, AB is a diameter of the circle,
cm and
cm. Find the area of the shaded region (Use
).
Solution From the given question, \[AC=6\]cm and \[BC=8\] cm We know that a triangle in a semi-circle with hypotenuse as diameter is right angled triangle. By using Pythagoras theorem in triangle...
Find the area of the flower bed (with semi-circular ends) shown in Fig. 11.6.
Solution: From the given figure, We got that the Length and breadth of the rectangular portion (AFDC) of the flower bed are \[38\] cm and \[10\] cm respectively. We know that, Area of the flower bed...
A cow is tied with a rope of length
m at the corner of a rectangular field of dimensions
. Find the area of the field in which the cow can graze.
Let us consider ABCD be a rectangular field. Given, Length of the field = \[20\] m Given, Breadth of the field = \[16\] m From the given question, A cow is tied with a rope at a point A. Let us...
The wheel of a motor cycle is of radius
cm. How many revolutions per minute must the wheel make so as to keep a speed of
km/h?
From the question Radius of wheel = r = \[35\] cm We know that one revolution of the wheel is equal to Circumference of the wheel i.e., \[2\pi r\] = \[2\times (22/7)\times 35\] = \[220\] cm But,...
Find the area of a sector of a circle of radius
cm and central angle
.
We know that Area of a sector of a circle = \[(1/2){{r}^{2}}\theta \], Here r is the radius and \[\theta \] is the angle in radians subtended by the arc at the center of the circle From the given...
In Fig. 11.5, a square of diagonal
cm is inscribed in a circle. Find the area of the shaded region.
Let us take a be the side of square. From the question we got, diagonal of square and diameter of circle is \[8\] cm In right angled triangle ABC, By Using Pythagoras theorem we got,...
Find the radius of a circle whose circumference is equal to the sum of the circumferences of two circles of radii
cm and
cm.
Given Radius of first circle = \[{{r}_{1}}\] = \[15\] cm Given Radius of second circle = \[{{r}_{2}}\] = \[18\] cm Therefore, Circumference of first circle of radius \[{{r}_{1}}\]= \[2\pi...
In covering a distance s metres, a circular wheel of radius r metres makes
revolutions. Is this statement true? Why?
The given statement is True Explanation: The distance travelled by a circular wheel of radius r m in one revolution is equal to the circumference of the circle = \[2\pi r\] So we got, Number of...
Is it true that the distance travelled by a circular wheel of diameter d cm in one revolution is
cm? Why?
The given statement is False Explanation: We know that, Circumference of the circle = \[2\pi d\](d is the diameter of the circle). Thus, the statement is false
Is it true to say that area of a segment of a circle is less than the area of its corresponding sector? Why?
The given statement is False Explanation: In major segment, area is not always greater than the are of its corresponding sector In minor segment, area is always greater than the area of its...
In Fig 11.3, a square is inscribed in a circle of diameter d and another square is circumscribing the circle. Is the area of the outer square four times the area of the inner square? Give reasons for your answer.
Solution: The given statement is False Explanation: From the fig, Let the Diameter of the circle = d Therefore, Diagonal of inner square (EFGH) = Side of the outer square (ABCD) = Diameter of circle...
Will it be true to say that the perimeter of a square circumscribing a circle of radius
cm is
cm? Give reasons for your answer.
The given statement is true Explanation: Let \[r\] be the radius of circle and is equal \[a\] cm Therefore, Diameter of the circle = d = \[2\times Radius\] = \[2a\] cm From the question we got that...
Is the area of the circle inscribed in a square of side a cm,
? Give reasons for your answer.
The given statement is false Explanation: Let us assume a be the side of square. From the question we got that the circle is inscribed in the square. Therefore, Diameter of circle = Side of square...
If the perimeter of a circle is equal to that of a square, then the ratio of their areas is (A)
(B)
(C)
(D)
The correct option is (B) \[14:11\] Explanation: Let us take r as the radius of the circle and a as the side of the square. From the given question, Perimeter of a circle of radius r = Perimeter of...
Area of the largest triangle that can be inscribed in a semi-circle of radius r units is (A)
sq. units (B)
sq. units (C)
sq. units (D)
sq. units
The correct option is (A) \[{{r}^{2}}\] sq. units Explanation: The largest triangle which can be inscribed in a semi-circle of radius r units is Base of triangle should be equal to the diameter of...
If the circumference of a circle and the perimeter of a square are equal, then (A) Area of the circle = Area of the square (B) Area of the circle > Area of the square (C) Area of the circle < Area of the square (D) Nothing definite can be said about the relation between the areas of the circle & square.
The correction option is (B) Area of the circle > Area of the square Explanation: From the given question, Circumference of a circle of radius r = Perimeter of a square of side a Let us take r...
If the sum of the circumferences of two circles with radii
and
is equal to the circumference of a circle of radius
, then (A)
(B)
(C)
(D) Nothing definite can be said about the relation among
,
&
.
The Correct option(A) \[{{R}_{1}}+{{R}_{2}}=R\] Explanation: From the given question, We got sum of the circumferences of two circles with radii \[R1\] and \[R2\] is equal to the circumference of a...
If the sum of the areas of two circles with radii
and
is equal to the area of a circle of radius
, then (A)
(B)
(C)
(D)
The Correct option is (B) \[R_{1}^{2}+R_{2}^{2}={{R}^{2}}\] Explanation: From the given question, We got sum of the areas of two circles with radii \[R1\] and \[R2\] is equal to the area of a circle...
Draw a right triangle ABC in which BC = 12 cm, AB = 5 cm and ∠B = 90°. Construct a triangle similar to it and of scale factor 2/3. Is the new triangle also a right triangle?
Steps of construction: Define a boundary portion \[AB\text{ }=\text{ }5\text{ }cm.\] Develop a right point \[SAB\]at point \[A.\] Draw a circular segment of span \[12\text{ }cm\]with \[B\]as its...
Draw a line segment of length 7 cm. Find a point P on it which divides it in the ratio 3:5.
Steps of construction: Define a boundary fragment, \[AB\text{ }=\text{ }7\text{ }cm.\] Draw a beam, \[AX\], making an intense point down ward with \[AB.\] Imprint the focuses\[{{A}_{1}},\text{...
To construct a triangle similar to a given △ABC with its sides 7/3 of the corresponding sides of △ABC, draw a ray BX making acute angle with BC and X lies on the opposite side of A with respect to BC. The points B1, B2, …., B7 are located at equal distances on BX, B3 is joined to C and then a line segment B6C‘ is drawn parallel to B3C where C‘ lies on BC produced. Finally, line segment A‘C‘ is drawn parallel to AC.
False Support: Allow us to attempt to build the figure as given in the inquiry. Steps of development, Define a boundary section \[BC.\] With \[B\text{ }and\text{ }C\]as focuses, draw two circular...
By geometrical construction, it is possible to divide a line segment in the ratio √3:(1/√3)
True Support: As per the inquiry, Ratio\[=\text{ }\surd 3\text{ }:\text{ }\left( \text{ }1/\surd 3 \right)\] On working on we get, \[\surd 3/\left( 1/\surd 3 \right)\text{ }=\text{ }\left( \surd...
Draw two concentric circles of radii
Taking a point on outer circle construct the pair of tangents to the other. Measure the length of a tangent and verify it by actual calculation.
Steps of construction: Draw a circle with focus \[\mathbf{O}\]and radius \[\mathbf{3}\text{ }\mathbf{cm}.\] Draw one more circle with focus \[\mathbf{O}\]and radius \[\mathbf{5}\text{...
Draw a parallelogram
in which
and angle
divide it into triangles
and
by the diagonal
Construct the triangle
similar to triangle
with scale factor
. Draw the line segment
parallel to
where
lies on extended side
. Is
a parallelogram?
Steps of construction: Define a boundary \[\mathbf{AB}=\mathbf{3}\text{ }\mathbf{cm}.\] Draw a beam \[\mathbf{BY}\]making an intense \[\angle \mathbf{ABY}=\mathbf{60}{}^\circ .\] With focus...
Two line segments
include an angle of
where
Locate points
respectively such that
Join
and measure the length
Steps of construction: 1.Define a boundary portion \[AB\text{ }=\text{ }5\text{ }cm.\] Draw \[\angle BAZ\text{ }=\text{ }60{}^\circ .\] With focus \[A\]and sweep\[7\text{ }cm\], draw a...
To divide a line segment
in the ratio
, draw a ray
such that
is an acute angle, then draw a ray
parallel to
and the points
and
are located at equal distances on ray
and
, respectively. Then the points joined are
\[\left( \mathbf{A} \right)\text{ }{{\mathbf{A}}_{\mathbf{5}}}~\mathbf{and}\text{ }{{\mathbf{B}}_{\mathbf{6}}}\] As per the inquiry, A line portion \[AB\]in the proportion \[5:7\] Along these...
To divide a line segment
in the ratio
, a ray
is drawn first such that
is an acute angle and then points
are located at equal distances on the ray
and the point
is joined to
SOLUTION:- \[\left( \mathbf{B} \right)\text{ }{{\mathbf{A}}_{\mathbf{11}}}\] As per the inquiry, A line section\[~AB\] in the proportion \[4:7\] Thus, \[A:B\text{ }=\text{ }4:7\] Presently, Draw a...
To divide a line segment
in the ratio
, first a ray
is drawn so that
is an acute angle and then at equal distances points are marked on the ray
such that the minimum number of these points is (A)
(B)
(C)
(D)
SOLUTION:- \[\left( D \right)\text{ }12\] As indicated by the inquiry, A line fragment \[AB\]in the proportion \[5:7\] In this way, \[A:B\text{ }=\text{ }5:7\] Presently, Draw a beam \[AX\]making an...
Find the sum of the integers between 100 and 200 that are
(i) divisible by 9
(ii) not divisible by 9
[Hint (ii): These numbers will be: Total numbers – Total numbers divisible by 9]
Solution: (i) The number divisible by 9 between 100 and 200 = 108, 117, 126,...198 Let n be the number of terms that are divisible by 9 and are between 100 and 200. ${{a}_{n}}~=\text{ }a\text{...
An AP consists of 37 terms. The sum of the three middle most terms is 225 and the sum of the last three is 429. Find the AP.
Solution: We all know that, First term of an AP = a The common difference = d AP’s nth term of an, ${{a}_{n}}~=a+\left( n1 \right)d$ Since, $n\text{ }=\text{ }37$ (odd), Middle term will be $\left(...
The eighth term of an AP is half its second term and the eleventh term exceeds one third of its fourth term by 1. Find the 15th term.
Solution: We all know that, AP’s first term = a AP’s common difference = d AP’s nth term, ${{a}_{n}}~=\text{ }a\text{ }+\text{ }\left( n\text{ }\text{ }1 \right)d$ According to the question,...
Find the
(i) Sum of those integers from 1 to 500 which are multiples of 2 or 5.
[Hint (i): These numbers will be: multiples of 2 + multiples of 5 – multiples of 2 as well as of 5]
Solution: We all know that, Multiple of 2 + Multiple of 5 - LCM Multiple (2, 5) = Multiples of 2 or 5 Multiple of 2 + Multiple of 5 – Multiple of LCM (10) = Multiples of 2 or 5 List of multiple of 2...
Find the
(i) Sum of those integers between 1 and 500 which are multiples of 2 as well as of 5.
(ii) Sum of those integers from 1 to 500 which are multiples of 2 as well as of 5 .
Solution: (i) It is known to us that, LCM of (2, 5) = 10 for multiples of 2 and 5. Between 1 and 500, multiples of 2 and 5 = 10, 20, 30,..., 490. As a result, We can say that 10, 20, 30,..., 490 is...
The sum of the first five terms of an AP and the sum of the first seven terms of the same AP is 167. If the sum of the first ten terms of this AP is 235, find the sum of its first twenty terms.
Solution: In an A.P, we know that, First term = a The common difference = d An AP’s number of terms of = n According to the question, We have, ${{S}_{5}}~+\text{ }{{S}_{7}}~=\text{ }167$ Using the...
Determine the AP whose fifth term is 19 and the difference of the eighth term from the thirteenth term is 20.
Solution: It is known to us that, AP’s first term = a The common difference = d. According to the question given, 5th term, ${{a}_{5}}~=\text{ }19$ Using the nth term formula, ${{a}_{n}}~=\text{...
Find a, b and c such that the following numbers are in AP: a, 7, b, 23, c.
Solution: The below given condition needs to be satisfied for a, 7, b, 23, c… to be in AP, ${{a}_{5}}-{{a}_{4}}~=\text{ }{{a}_{4}}-{{a}_{3}}~=\text{ }{{a}_{3}}-{{a}_{2}}~=\text{...
Write the first three terms of the APs when a and d are as given below:
(i) a = 2, d = 1/√2
Solution: (i) It is known to us that, AP’s first three terms are : a, a + d, a + 2d √2, √2+1/√2, √2+2/√2 √2, 3/√2, 4/√2
Write the first three terms of the APs when a and d are as given below:
(i) a =1/2, d = -1/6
(ii) a = –5, d = –3
Solution: (i) It is known to us that, AP’s first three terms are : a, a + d, a + 2d ${\scriptscriptstyle 1\!/\!{ }_2},\text{ }{\scriptscriptstyle 1\!/\!{ }_2}\text{ }+\text{ }\left( -1/6...
Verify that each of the following is an AP, and then write its next three terms.
(i) a, 2a + 1, 3a + 2, 4a + 3,…
Solution: Given Here a1 = a ${{a}_{2}}~=\text{ }2a\text{ }+\text{ }1$ ${{a}_{3}}~=\text{ }3a\text{ }+\text{ }2$ ${{a}_{4}}~=~4a\text{ }+\text{ }3$ ${{a}_{2}}-{{a}_{1}}~=\text{ }\left( 2a\text{...
Verify that each of the following is an AP, and then write its next three terms.
(i) √3 , 2√3, 3√3,…
(ii) a + b, (a + 1) + b, (a + 1) + (b + 1), …
Solution: (i) Given here, ${{a}_{1~}}=\surd 3$ ${{a}_{2}}~=2\surd 3$ ${{a}_{3}}~=3\surd 3$ ${{a}_{4}}~=4\surd 3$ ${{a}_{2}}-{{a}_{1}}=2\sqrt{3}-\sqrt{3}=\sqrt{3}$ ${{a}_{3}}-{{a}_{2}}~=3\surd...
Verify that each of the following is an AP, and then write its next three terms.
(i) 0, 1/4, 1/2, 3/4,…
(ii) 5, 14/3, 13/3, 4…
Solution: (i) Given here, ${{a}_{1~}}=0$ ${{a}_{2}}~=\text{ }{\scriptscriptstyle 1\!/\!{ }_4}$ ${{a}_{3}}~=\text{ }{\scriptscriptstyle 1\!/\!{ }_2}$ ${{a}_{4}}~=\text{ }{\scriptscriptstyle 3\!/\!{...
Match the APs given in column A with suitable common differences given in column B.
Column A Column B (A1) 2, – 2, – 6, –10,… (B1) 2/3 (A2) a = –18, n = 10, an = 0 (B2) – 5 (A3) a = 0, a10 = 6 (B3) 4 (A4) a2 = 13, a4 =3 (B4) – 4 (B5) 2 (B6) 1/2 (B7) 5 Solution: (A1) AP is 2, – 2, –...
Two APs have the same common difference. The first term of one AP is 2 and that of the other is 7 The difference between their 10th terms is the same as the difference between their 21st terms, which is the same as the difference between any two corresponding terms. Why?
Solution: Consider two APs with the first terms as ‘a’ and ‘A’. The common differences are ‘d’ and ‘D’, respectively. Assume that n is any term. ${{a}_{n}}~=a+\left( n-1 \right)d$ ${{A}_{n}}~=\text{...
For the AP: –3, –7, –11, …, can we find directly a30 – a20 without actually finding a30 and a20? Give reasons for your answer.
Solution: True Provided that The first term, $a=-3$ The common difference, $d=\text{ }{{a}_{2}}~-{{a}_{1}}~=-7\left( -\text{ }3 \right)=-4$ ${{a}_{30}}-{{a}_{20}}~=\text{ }a+29d-\left( a\text{...
Justify whether it is true to say that –1, -3/2, –2, 5/2,… forms an AP as a2 – a1 = a3 – a2.
Solution: False ${{a}_{1}}~=\text{ }-1,\text{ }{{a}_{2}}~=\text{ }-3/2,\text{ }{{a}_{3}}~=\text{ }-2$and ${{a}_{4}}~=\text{ }5/2$ ${{a}_{2}}-{{a}_{1~}}=-3/2\left( -1 \right)\text{ }=-1/{{}_{2}}$...
Which of the following form an AP? Justify your answer.
(i) √3, √12, √27, √48, …
Solution: We have, ${{a}_{1~}}=\text{ }\surd 3$ $,{{a}_{2}}~=\text{ }\surd 12,\text{ }{{a}_{3}}~=\text{ }\surd 27$ and ${{a}_{4}}~=\text{ }\surd 48$ ${{a}_{2}}~-{{a}_{1~}}=\text{ }\surd 12-\surd...
Which of the following form an AP? Justify your answer.
(i) 1/2,1/3,1/4, …
(ii) 2, 22, 23, 24, …
Solution: (i) We have ${{a}_{1}}~=\text{ }{\scriptscriptstyle 1\!/\!{ }_2}~,\text{ }{{a}_{2}}~=\text{ }1/3~$and ${{a}_{3}}~=~{\scriptscriptstyle 1\!/\!{ }_4}$ ${{a}_{2}}~-{{a}_{1}}~=-1/6$ We can...
Which of the following form an AP? Justify your answer.
(i) 1, 1, 2, 2, 3, 3…
(ii) 11, 22, 33…
Solution: (i) We have ${{a}_{1}}~=\text{ }1\text{ },\text{ }{{a}_{2}}~=\text{ }1,\text{ }{{a}_{3}}~=\text{ }2$ and ${{a}_{4}}~=\text{ }2$ ${{a}_{2}}~-{{a}_{1}}~=\text{ }0$...
Which of the following form an AP? Justify your answer.
(i) –1, –1, –1, –1,…
(ii) 0, 2, 0, 2,…
Solution: (i) We have${{a}_{1}}~=-1\text{ },\text{ }{{a}_{2}}~=-1$, ${{a}_{3}}~=-1$and ${{a}_{4}}~=-1$ ${{a}_{2}}~-{{a}_{1}}~=\text{ }0$ ${{a}_{3}}~-{{a}_{2}}~=\text{ }0$...
Choose the correct answer from the given four options in the following questions: If the common difference of an AP is 5, then what is a18 – a13?
(A) 5 (B) 20 (C) 25 (D) 30
Solution: Option (C) 25 is the correct answer. Explanation: Provided, the common difference of AP i.e., d = 5 Now, As it is known, an AP’s nth term is ${{a}_{n\text{ }}}=~a+\left( n-1 \right)d$...
Choose the correct answer from the given four options in the following questions: Which term of the AP: 21, 42, 63, 84… is 210?
(A) 9th (B) 10th (C) 11th (D) 12th
Solution: Option (B) 10th is the correct answer. Explanation: Let the given AP’s nth term be 210. According to question, first term, $a=21$ common difference, $d=42-21=21$and ${{a}_{n}}~=210$ We...
Choose the correct answer from the given four options in the following questions: If the 2nd term of an AP is 13 and the 5th term is 25, what is its 7th term?
(A) 30 (B) 33 (C) 37 (D) 38
Solution: Option (B) 33 is the correct option. Explanation: It is known that the AP’s nth term is ${{a}_{n\text{ }}}=~a\text{ }+\text{ }\left( n-1 \right)d$ In which, first term = a nth term = an...
Choose the correct answer from the given four options in the following questions: The 21st term of the AP whose first two terms are –3 and 4 is
(A) 17 (B) 137 (C) 143 (D) –143
Solution: Option (B) 137 is the correct option. Explanation: First two terms of an AP are $a=-3$and${{a}_{2\text{ }}}=~4$. It is known, nth term of an AP is ${{a}_{n\text{ }}}=~a\text{ }+\text{...
Choose the correct answer from the given four options in the following questions: The first four terms of an AP, whose first term is –2 and the common difference is –2, are
(A) – 2, 0, 2, 4 (B) – 2, 4, – 8, 16 (C) – 2, – 4, – 6, – 8 (D) – 2, – 4, – 8, –16
Solution: Option (C) – 2, – 4, – 6, – 8 is the correct answer. Explanation: First term, a = – 2 Second Term, d = – 2 ${{a}_{1\text{ }}}=~a=\text{ -}2$ It is known that the AP’s nth term is...
Choose the correct answer from the given four options in the following questions: The 11th term of the AP: –5, (–5/2), 0, 5/2, …is (A) –20 (B) 20 (C) –30 (D) 30
Solution: Option (B) 20 is the correct answer. Explanation: First term, a = – 5 Common difference, $d=5-\left( -5/2 \right)=5/2$ $n\text{ }=\text{ }11$ It is known that the AP’s nth term is...
Choose the correct answer from the given four options in the following questions: The list of numbers – 10, – 6, – 2, 2,… is (A) an AP with d = – 16 (B) an AP with d = 4 (C) an AP with d = – 4 (D) not an AP
Solution: Option (B) an AP with d = 4 is the correct answer. Explanation: According to the question, ${{a}_{1\text{ }}}=~\text{ }-10$ ${{a}_{2\text{ }}}=\text{ }-6$ ${{a}_{3\text{ }}}=~\text{ }-2$...
Choose the correct answer from the given four options in the following questions: In an AP, if a = 3.5, d = 0, n = 101, then an will be (A) 0 (B) 3.5 (C) 103.5 (D) 104.5
Solution: Option (B) 3.5 is the correct answer. Explanation: It is known that nth term of an AP is ${{a}_{n\text{ }=}}~a+\left( n1 \right)d$ In which, first term = a nth term = an common difference...
Find the value of x for which DE||AB in given figure.
Solution: According to the given question, DE || AB By the basic proportionality theorem, $CD/AD\text{ }=\text{ }CE/BE$ Therefore, when a line is drawn parallel to one of the triangle's sides and...
Is the triangle with sides 25 cm, 5 cm and 24 cm a right triangle? Give reason for your answer.
Solution: False According to the given question, Let’s assume that, $A\text{ }=\text{ }25\text{ }cm$ $B\text{ }=\text{ }5\text{ }cm$ $C\text{ }=\text{ }24\text{ }cm$ Using the Pythagoras Theorem, We...
The points A (x1, y1), B (x2, y2) and C (x3 y3) are the vertices of ABC.
(i) Find the coordinates of points Q and R on medians BE and CF, respectively such that BQ : QE = 2 : 1 and CR : RF = 2 : 1
(ii) What are the coordinates of the centroid of the triangle ABC?
Solution: (i) Let (p, q) be the coordinates of a point Q. Provided, The point Q (p, q), Divide the line joining $\mathrm{B}\left(\mathrm{x}{2}, \mathrm{y}{2}\right)$ and...
The points A (x1, y1), B (x2, y2) and C (x3 y3) are the vertices of ABC. (i) The median from A meets BC at D. Find the coordinates of the point D. (ii) Find the coordinates of the point P on AD such that AP : PD = 2 : 1
Solution: According to the given question, A, B and C are the vertices of ΔABC A(x1, y1), B(x2, y2), C(x3, y3) are the coordinates of A, B and C. (i) According to the information provided, D is BC's...
A (6, 1), B (8, 2) and C (9, 4) are three vertices of a parallelogram ABCD. If E is the midpoint of DC, find the area of △ ADE.
Solution: According to the given question, A (6, 1), B (8, 2) and C (9, 4) are the three vertices of a parallelogram ABCD Let (x, y) be the fourth vertex of parallelogram. It is known to us that,...
Choose the correct answer from the given four options in the following questions: In an AP, if d = –4, n = 7, an = 4, then a is (A) 6 (B) 7 (C) 20 (D) 28
Solution: Option (D) 28 is the correct answer. Explanation: It is known that nth term of an AP is ${{a}_{n\text{ }=}}~a+\left( n-1 \right)d$ In which, first term = a nth term = an common difference...
If (– 4, 3) and (4, 3) are two vertices of an equilateral triangle, find the coordinates of the third vertex, given that the origin lies in the interior of the triangle.
Solution: Let (x,y) be the vertices. The distance between (x,y) & (4,3) is $=\text{ }\surd ({{\left( x-4 \right)}^{2}}~+\text{ }{{\left( y-3 \right)}^{2}})$……(1) The distance between (x,y) &...
In what ratio does the x–axis divide the line segment joining the points (– 4, – 6) and (–1, 7)? Find the coordinates of the point of division.
Solution: Let 1: k be the ratio in which x-axis divides the line segment joining (–4, –6) and (–1, 7). Therefore, x-coordinate is (-1 – 4k) / (k + 1) y-coordinate is (7 – 6k) / (k + 1) y coordinate...
Find the area of the triangle whose vertices are (–8, 4), (–6, 6) and (–3, 9).
Solution: The provided vertices are: $({{x}_{1}},\text{ }{{y}_{1}})\text{ }=\text{ }\left( -8,\text{ }4 \right)$ $({{x}_{2}},\text{ }{{y}_{2}})\text{ }=\text{ }\left( -6,\text{ }6 \right)$...
If the point A (2, – 4) is equidistant from P (3, 8) and Q (–10, y), find the values of y. Also find distance PQ.
Solution: $A(2,-4), P(3,8)$ and $Q(-10, y)$ are the given points. Now according to the question given, $$ \begin{aligned} P A &=Q A \\ \sqrt{(2-3)^{2}+(-4-8)^{2}} &=\sqrt{(2+10)^{2}+(-4-y)^{2}} \\...
Find the value of m if the points (5, 1), (–2, –3) and (8, 2m) are collinear.
Solution: The points given here i.e., A(5, 1), B(–2, –3) and C(8, 2m) are collinear. Therefore the area of ∆ABC = 0 ${\scriptscriptstyle 1\!/\!{ }_2}\text{ }[{{x}_{1}}~({{y}_{2}}~\text{...
Find the coordinates of the point Q on the x–axis which lies on the perpendicular bisector of the line segment joining the points A (–5, –2) and B(4, –2). Name the type of triangle formed by the points Q, A and B.
Solution: As the point P lies on the perpendicular bisector of AB, point Q is the midpoint of AB . By the formula for midpoint: $({{x}_{1}}~+\text{ }{{x}_{2}})/2\text{ }=\text{ }\left( -5+4...
Find a point which is equidistant from the points A (–5, 4) and B (–1, 6)? How many such points are there?
Solution: Let P be the point. Now according to the given question, P is at equal distance from A (–5, 4) and B (–1, 6) Then the point P $=\text{ }(({{x}_{1}}+{{x}_{2}})/2,\text{...
Find the value of a, if the distance between the points A (–3, –14) and B (a, –5) is 9 units.
Solution: The distance between the two points (x1,y1) ( x2,y2) : $d=\surd ({{x}_{2}}-{{x}_{1}}){}^\text{2}+({{y}_{2}}-{{y}_{1}}){}^\text{2}$ The distance between A (–3, –14) and B (a, –5): $=\surd...
What type of a quadrilateral do the points A (2, –2), B (7, 3), C (11, –1) and D (6, –6) taken in that order, form?
Solution: A (2, –2), B (7, 3), C (11, –1) and D (6, –6) are the given points. Now using the distance formula, $d~=\text{ }\surd \text{ }({{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{...
Find the points on the x–axis which are at a distance of 2√5 from the point (7, –4). How many such points are there?
Solution: (x, 0) = Let coordinates of the point (given that the point lies on x axis) ${{x}_{1}}=7.\text{ }{{y}_{1}}=-4$ ${{x}_{2}}=x.\text{ }{{y}_{2}}=0$ Distance $=\surd...
Name the type of triangle formed by the points A (–5, 6), B (–4, –2) and C (7, 5).
Solution: A (–5, 6), B (–4, –2) and C (7, 5) are the given points. Now, using the distance formula, $d~=\text{ }\surd \text{ }({{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{ }{{({{y}_{2}}~\text{...
State whether the following statements are true or false. Justify your answer. Points A (4, 3), B (6, 4), C (5, –6) and D (–3, 5) are the vertices of a parallelogram.
Solution: The statement given in the question is false. Justification: A (4, 3), B (6, 4), C (5, –6) and D (–3, 5) are the points given. We need to find the distance between A and B...
State whether the following statements are true or false. Justify your answer. Points A (3, 1), B (12, –2) and C (0, 2) cannot be the vertices of a triangle.
Solution: The statement given in the question is true. Justification: Coordinates of A $=\text{ }({{x}_{1}},\text{ }{{y}_{1}})\text{ }=\text{ }\left( 3,\text{ }1 \right)$ Coordinates of B $=\text{...
State whether the following statements are true or false. Justify your answer. Point P (0, 2) is the point of intersection of y–axis and perpendicular bisector of line segment joining the points A (–1, 1) and B (3, 3).
Solution: The statement given in the question is false. Justification: We know that the points on the perpendicular bisector of the line segment joining two points are equidistant from the two...
State whether the following statements are true or false. Justify your answer. The points (0, 5), (0, –9) and (3, 6) are collinear.
Solution: The statement given in the question is false. Justification: If the area of a triangle formed by its points equals 0, then the points are collinear. Provided, ${{x}_{1}}~=\text{ }0,\text{...
State whether the following statements are true or false. Justify your answer. Point P (– 4, 2) lies on the line segment joining the points A (– 4, 6) and B (– 4, – 6).
Solution: The statement given in the question is true. Justification: Equation of the line conatining the points A and B using the two-point form is, $\frac{y-6}{x+4}=\frac{-6-6}{-4+4}$...
State whether the following statements are true or false. Justify your answer. △ABC with vertices A (–2, 0), B (2, 0) and C (0, 2) is similar to △DEF with vertices D (–4, 0) E (4, 0) and F (0, 4).
Solution: The statement given in the question is true. Justification: Distance formula, $d~=\text{ }\surd \text{ }({{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{ }{{({{y}_{2}}~\text{...
Form the pair of linear equations for the following problems and find their solution by substitution method.(i) The difference between two numbers is 26 and one number is three times the other. Find them.(ii) The larger of two supplementary angles exceeds the smaller by 18 degrees. Find them.
Arrangement (i): Leave the two numbers alone x and y individually, to such an extent that y > x. As indicated by the inquiry, \[y\text{ }=\text{ }3x\text{ }\ldots \text{ }\ldots \text{ }\ldots...
Choose the correct answer from the given four options in the following questions: The distance of the point P (–6, 8) from the origin is (A) 8 (B) 2√7 (C) 10 (D) 6
Solution: Option (C) 10 is the correct answer. The formula for distance: ${{d}^{2}}~=\text{ }{{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{ }{{({{y}_{2}}~\text{ }{{y}_{1}})}^{2}}$ According to the...
Choose the correct answer from the given four options in the following questions: The area of a triangle with vertices A (3, 0), B (7, 0) and C (8, 4) is (A) 14 (B) 28 (C) 8 (D) 6
Solution: Option (C) 8 is the correct answer. The vertices of the triangle are, $A\text{ }({{x}_{1}},\text{ }{{y}_{1}})=\left( 3,\text{ }0 \right)$ $B\text{ }({{x}_{2}},\text{ }{{y}_{2}})=\left(...
Choose the correct answer from the given four options in the following questions: The perimeter of a triangle with vertices (0, 4), (0, 0) and (3, 0) is (A) 5 (B) 12 (C) 11 (D) 7+ √5
Solution: Option (B) 12 is the correct answer. (0, 4), (0, 0) and (3, 0) are the vertices of a triangle. The perimeter of triangle AOB = Sum of the length of all its sides: = distance between...
Choose the correct answer from the given four options in the following questions: AOBC is a rectangle whose three vertices are vertices A (0, 3), O (0, 0) and B (5, 0). The length of its diagonal is (A) 5 (B) 3 (C) √34 (D) 4
Solution: Option (C) √34 is the correct answer. The three vertices are: $A\text{ }=\text{ }\left( 0,\text{ }3 \right)$, $O\text{ }=\text{ }\left( 0,\text{ }0 \right)$ , $B\text{ }=\text{ }\left(...
Choose the correct answer from the given four options in the following questions: The distance between the points (0, 5) and (–5, 0) is (A) 5 (B) 5√2 (C) 2√5 (D) 10
Solution: Option (B) 5√ 2 is the correct answer. Distance formula: ${{d}^{2}}~=\text{ }{{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{ }{{({{y}_{2}}~\text{ }{{y}_{1}})}^{2}}$ According to the given...
Choose the correct answer from the given four options in the following questions: The distance between the points A (0, 6) and B (0, –2) is (A) 6 (B) 8 (C) 4 (D) 2
Solution: Option (B) 8 is the correct answer. The formula for distance : ${{d}^{2}}~=\text{ }{{({{x}_{2}}~\text{ }{{x}_{1}})}^{2}}~+\text{ }{{({{y}_{2}}~\text{ }{{y}_{1}})}^{2}}$ According to the...
Choose the correct answer from the given four options in the following questions: The distance of the point P (2, 3) from the x-axis is (A) 2 (B) 3 (C) 1 (D) 5
Solution: Option (B) 3 is the correct answer. We all know that, On the Cartesian plane (x, y) is a point in first quadrant. Then, Perpendicular distance from Y–axis = x, and Perpendicular distance...
A flag pole 18 m high casts a shadow 9.6 m long. Find the distance of the top of the pole from the far end of the shadow.
Solution: Let MN the flag pole = 18 m and its shadow LM = 9.6 m. The distance of the top of the pole be LN, N from the far end, L of the shadow. By Pythagoras theorem in right angled ∆LMN,...
For going to a city B from city A, there is a route via city C such that AC⊥CB, AC = 2 x km and CB = 2 (x + 7) km. It is proposed to construct a 26 km highway which directly connects the two cities A and B. Find how much distance will be saved in reaching city B from city A after the construction of the highway.
Solution: According to the given question, AC⊥CB, $AC\text{ }=\text{ }2x\text{ }km$, $CB=2\left( x+7 \right)km$ and $AB=26\text{ }km$ As a result, we get triangle ACB right angled at C. Now, using...
A 5 m long ladder is placed leaning towards a vertical wall such that it reaches the wall at a point 4 m high. If the foot of the ladder is moved 1.6 m towards the wall, then find the distance by which the top of the ladder would slide upwards on the wall.
Solution: Let 5 m be the length of the ladder AC. Let 4m be the height of the wall on which ladder is placed is BC From right angled triangle EBD, Now using the Pythagoras Theorem,...
In Fig 6.17, if PQRS is a parallelogram and AB||PS, then prove that OC||SR.
Solution: According to the given question, The given figure PQRS is a parallelogram, As a result, PQ || SR and PS || QR. It is also given that, AB || PS. To prove: OC || SR From triangles OPS and...
Prove that if a line is drawn parallel to one side of a triangle to intersect the other two sides, then the two sides are divided in the same ratio.
Solution: Let's assume a triangle ABC in which a line DE parallel to BC intersects AB at D and AC at E. To prove: The two sides are divided by DE in the same ratio. $AD/DB\text{ }=\text{ }AE/EC$...
It is given that ∆ ABC ~ ∆ EDF such that AB = 5 cm, AC = 7 cm, DF= 15 cm and DE = 12 cm. Find the lengths of the remaining sides of the triangles.
Solution: According to the given question, ∆ABC ∼ ∆EDF By the property of similar triangle, we all know that, corresponding sides of ∆ABC and ∆EDF are in the same ratio. $AB/ED\text{ }=\text{...
In Fig. 6.16, if ∠A = ∠C, AB = 6 cm, BP = 15 cm, AP = 12 cm and CP = 4 cm, then find the lengths of PD and CD.
Solution: According to the given question, $\angle A\text{ }=~\angle C$, $AB\text{ }=\text{ }6\text{ }cm$, $BP\text{ }=\text{ }15\text{ }cm$, $AP\text{ }=\text{ }12\text{ }cm$ $CP\text{ }=\text{...
If ∆ABC ∼ ∆DEF, AB = 4 cm, DE = 6, EF = 9 cm and FD = 12 cm, then find the perimeter of ∆ABC.
Solution: According to the given question, $AB\text{ }=\text{ }4\text{ }cm$, $DE\text{ }=\text{ }6\text{ }cm$ $EF\text{ }=\text{ }9\text{ }cm$ $FD\text{ }=\text{ }12\text{ }cm$ Also, ∆ABC ∼ ∆DEF We...
Find the altitude of an equilateral triangle of side 8 cm.
Solution: Let an equilateral triangle of side 8 cm be ABC. $AB\text{ }=\text{ }BC\text{ }=\text{ }CA\text{ }=\text{ }8\text{ }cm$. (all sides of an equilateral triangle is equal) Construct an...
In figure, if AB || DC and AC, PQ intersect each other at the point O. Prove that OA.CQ = 0C.AP.
Solution: According to the given question, At point O, AC and PQ intersect each other and AB||DC. From triangles AOP and COQ, $\angle AOP\text{ }=~\angle COQ$[As they are vertically opposite angles]...
Diagonals of a trapezium PQRS intersect each other at the point 0, PQ || RS and PQ = 3 RS. Find the ratio of the areas of Δ POQ and Δ ROS.
Solution: According to the given question, The given figure, PQRS is a trapezium in which PQ || RS and PQ = 3RS $PQ/RS\text{ }=\text{ }3/1\text{ }=\text{ }3$…(i) In triangles POQ and ROS, $\angle...
In figure, if ∠1 =∠2 and ΔNSQ = ΔMTR, then prove that ΔPTS ~ ΔPRQ.
Solution: According to the given question, $\text{ }\Delta NSQ~\cong ~\Delta MTR$ $\angle 1\text{ }=~\angle 2$ Since, $\Delta NSQ\text{ }=\text{ }\Delta MTR$ As a result, $SQ\text{ }=\text{...
In a ΔPQR, PR2 – PQ2 = QR2 and M is a point on side PR such that QM ⊥ PR. Prove that QM2 =PM × MR.
Solution: According to the given question, In triangle PQR, $P{{R}^{2}}~=\text{ }Q{{R}^{2}}$ and QM⊥PR Using the Pythagoras theorem, we obtain, $P{{R}^{2}}~=\text{ }P{{Q}^{2}}~+\text{ }Q{{R}^{2}}$...
Two dice are thrown together. Find the probability that the product of the numbers on the top of the dice is (i) 6 (ii) 12 (iii) 7
Number of absolute results = 36 (I) When result of the numbers on the highest point of the dice = 6. The potential results = (1, 6), (2,3), (3, 2), (6, 1). Subsequently, number of conceivable ways =...
Two dice are thrown simultaneously. What is the probability that the sum of the numbers appearing on the dice is (i) 7? (ii) a prime number? (iii) 1?
As indicated by the inquiry, Two dice are tossed all the while. In this way, that number of potential results = 36 (I) Sum of the numbers showing up on the dice is 7. Thus, the potential...
Two dice are thrown at the same time. Find the probability of getting A Same number on both dice. Different numbers on both dice.
Two dice are tossed simultaneously. Along these lines, absolute number of potential results = 36 (I) Same number on both dice. Potential results = (1,1), (2,2), (3, 3), (4, 4), (5, 5), (6,...
The weight of coffee in 70 packets are shown in the following table : Weight (in g) Number of packets 200-201 12 201-202 26 202-203 20 203-204 9 204-205 2 205-206 1 Determine the modal weight.
In the given information, the most noteworthy recurrence is 26, which lies in the stretch 201 – 202 Here, l = 201,fm = 26,f1 = 12,f2 = 20 and (class width) h = 1 Subsequently, the modular weight =...
The monthly income of 100 families are given as below : Income (in Rs) Number of families 0-5000 8 5000-10000 26 10000-15000 41 15000-20000 16 20000-25000 3 25000-30000 3 30000-35000 2 35000-40000 1 Calculate the modal income.
As per the information given, The most elevated recurrence = 41, 41 lies in the stretch 10000 – 15000. Here, l = 10000, fm = 41,f1 = 26,f2 = 16 and h = 5000 \[=\text{ }10000\text{ }+\text{...
The maximum bowling speeds, in km per hour, of 33 players at a cricket coaching centre are given as follows: Speed (km/h) 85-100 100-115 115-130 130-145 Number of players 11 9 8 5 Calculate the median bowling speed.
First we develop the combined recurrence table Speed ( in km/h) Number of players Cumulative recurrence 85 – 100 11 11 100 – 115 ...
Weekly income of 600 families is tabulated below : Weekly income Number of families (in Rs) 0-1000 250 1000-2000 190 2000-3000 100 3000-4000 40 4000-5000 15 5000-6000 5 Total 600 Compute the median income.
Week by week Income Number of families (fi) Cumulative recurrence (cf) 0-1000 250 250 1000-2000 190 250 + 190 = 400 2000-3000 100 440 + 100 = 540...
Given below is a cumulative frequency distribution showing the marks secured by 50 students of a class: Marks Below 20 Below 40 Below 60 Below 80 Below 100 Number of students 17 22 29 37 50 Form the frequency distribution table for the data.
The recurrence circulation table for given information. Marks Number of understudies 0 – 20 12 20 – 40 22 – 17 = 5 40 – 60 29 – 22 = 7 60 – 80 37 – 29 = 8 80 – 100 50 – 37 =...
The following are the ages of 300 patients getting medical treatment in a hospital on a particular day: Age (in years) 10-20 20-30 30-40 40-50 50-60 60-70 Number of patients 60 42 55 70 53 20 Form: ALess than type cumulative frequency distribution. More than type cumulative frequency distribution
(I) Less than type Age (in year) Number of patients Under 10 0 Under 20 60 + 0 = 60 Under 30 60 + 42 = 102 Under 40 102 + 55 = 157 Under...
Find the unknown entries a, b, c, d, e, f in the following distribution of heights of students in a class: Height Frequency Cumulative frequency (in cm) 150-155 12 a 155-160 b 25 160-165 10 c 165-170 d 43 170-175 e 48 175-180 2 f Total 50
Tallness (in cm) Frequency Cumulative recurrence given Cumulative recurrence 150 – 155 12 a 12 155 – 160 b ...
Form the frequency distribution table from the following data : Marks (out of 90) Number of candidates More than or equal to 80 4 More than or equal to 70 6 More than or equal to 60 11 More than or equal to 50 17 More than or equal to 40 23 More than or equal to 30 27 More than or equal to 20 30 More than or equal to 10 32 More than or equal to 0 34
The recurrence dissemination table for the given information is: Class Interval Number of understudies 0-10 34 – 32 = 2 10-20 32 – 30 = 2 20-30 30 – 27 = 3 30-40 27 – 23 = 4...
The following table shows the cumulative frequency distribution of marks of 800 students in an examination: Marks Number of students Below 10 10 Below 20 50 Below 30 130 Below 40 270 Below 50 440 Below 60 570 Below 70 670 Below 80 740 Below 90 780 Below 100 800 Construct a frequency distribution table for the data above.
The recurrence circulation table for the given information is: Class Interval Number of understudies 0-10 10 10-20 50 – 10 = 40 20-30 130 – 50 = 80 30-40 270 – 130 = 140...
The following is the distribution of weights (in kg) of 40 persons : Weight (in kg) 40-45 45-50 50-55 55-60 60-65 65-70 70-75 75-80 Number of persons 4 4 13 5 6 5 2 1 Construct a cumulative frequency distribution (of the less than type) table for the data above.
Weight (in kg) Cumulative recurrence Under 45 4 Under 50 4 + 4 = 8 Under 55 8 + 13 = 21 Under 60 21 + 5 = 26 Under 65 26 + 6 = 32 Under...
The mileage (km per litre) of 50 cars of the same model was tested by a manufacturer and details are tabulated as given below : Mileage (km/l) 10-12 12-14 14-16 16-18 Number of cars 7 12 18 13 Find the mean mileage. The manufacturer claimed that the mileage of the model was 16 km/litre. Do you agree with this claim?
Mileage (km L-1) Class – Marks (xi) Number of vehicles (fi) fixi 10 – 12 11 7 77 12 – 14 13 12 156 14 – 16 15 ...
The weights (in kg) of 50 wrestlers are recorded in the following table : Weight (in kg) 100-110 110-120 120-130 130-140 140-150 Number of wrestlers 4 14 21 8 3 Find the mean weight of the wrestlers.
Weight (in kg) Number of Wrestlers (fi) Class Marks (xi) Deviation (di = xi – a) fidi 100 – 110 4 105 –20 –80 110 – 120 14 ...
An aircraft has 120 passenger seats. The number of seats occupied during 100 flights is given in the following table : Number of seats 100-104 104-108 108-112 112-116 116-120 Frequency 15 20 32 18 15 Determine the mean number of seats occupied over the flights.
Class Interval Class Marks (xi) Frequency (fi) Deviation (di = xi – a) fidi 100 – 104 102 15 –8 –120 104 – 108 106 ...
The daily income of a sample of 50 employees are tabulated as follows : Income (in Rs) 1-200 201-400 401-600 601-800 Number of employees 14 15 14 7 Find the mean daily income of employees.
C.I xi di = (xi – a) Fi fidi 1 – 200 100.5 –200 14 –2800 201 – 400 300.5 0 15 0 401 – 600 ...
The following tabe gives the number of pages written by Sarika for completing her own book for 30 days : Number of pages written per day 16-18 19-21 22-24 25-27 28-30 Number of days 1 3 4 9 13 Find the mean number of pages written per day.
Class Marks Mid – Value (xi) Number of days (fi) fixi 15.5 – 18.5 17 1 17 18.5 – 21.5 20 3 60 21.5 – 24.5 ...
Calculate the mean of the following data : Class 4 – 7 8 –11 12– 15 16 –19 Frequency 5 4 9 10
The given information isn't constant. Thus, we deduct 0.5 from as far as possible and add 0.5 in the maximum furthest reaches of each class. Class Class Marks (xi) Frequency (fi) fixi 3.5...
Calculate the mean of the scores of 20 students in a mathematics test : Marks 10-20 20-30 30-40 40-50 50-60 Number of students 2 4 7 6 1
We first, discover the class mark xi of each class and afterward continue as follows Class Class Marks (xi) Frequency (fi) fixi 10-20 15 2 30 20-30 ...
Find the mean of the distribution : Class 1-3 3-5 5-7 7-10 Frequency 9 22 27 17
We first, discover the class mark xi of each class and afterward continue as follows. Class Class Marks (xi) Frequency (fi) fixi 1-3 2 9 18 3-5 ...
In calculating the mean of grouped data, grouped in classes of equal width, we may use the formula where a is the assumed mean. a must be one of the mid-points of the classes. Is the last statement correct? Justify your answer.
No, the assertion isn't right. It isn't required that expected mean ought to be the mid – mark of the class span. a can be considered as any worth which is not difficult to work on it.
The median of an ungrouped data and the median calculated when the same data is grouped are always the same. Do you think that this is a correct statement? Give reason.
To ascertain the middle of an assembled information, the recipe utilized depends with the understanding that the perceptions in the classes are consistently disseminated or similarly divided....
Is it true to say that the mean, mode and median of grouped data will always be different? Justify your answer.
No, the upsides of mean, mode and middle of gathered information can be equivalent to well, it relies upon the sort of information given.
Will the median class and modal class of grouped data always be different? Justify your answer.
The middle class and modular class of assembled information isn't generally unique, it relies upon the information given.
In a family having three children, there may be no girl, one girl, two girls or three girls. So, the probability of each is ¼. Is this correct? Justify your answer.
No it isn't right that in a family having three youngsters, there might be no young lady, one young lady, two young ladies or three young ladies, the likelihood of each is ¼. . Let young men be B...
A game consists of spinning an arrow which comes to rest pointing at one of the regions (1, 2 or 3) (Fig. 13.1). Are the outcomes 1, 2 and 3 equally likely to occur? Give reasons.
All out no. of result = 360 \[p\left( 1 \right)=\text{ }90/360\text{ }=1/4\] \[p\left( 2 \right)\text{ }=\text{ }90/360\text{ }=\text{ }1/4\] \[p\left( 3 \right)\text{ }=\text{ }180/360\text{...
Apoorv throws two dice once and computes the product of the numbers appearing on the dice. Peehu throws one die and squares the number that appears on it. Who has the better chance of getting the number 36? Why?
Apoorv toss two dice on the double. Thus, the all out number of results = 36 Number of results for getting item 36 = 1(6×6) ∴ Probability for Apoorv = 1/36 Peehu tosses one kick the bucket, Thus,...
Which of the following cannot be the probability of an event? (A)1/3 (B) 0.1 (C) 3% (D)17/16
(D)17/16 Clarification: Likelihood of an occasion consistently lies somewhere in the range of 0 and 1. Likelihood of any occasion can't be mutiple or negative as (17/16) > 1 Consequently, choice...
If an event cannot occur, then its probability is (A)1 (B) ¾ (C) ½ (D) 0
(D) 0 Clarification: The occasion which can't happen is supposed to be incomprehensible occasion. The likelihood of incomprehensible occasion = zero. Thus, choice (D) is right
Consider the following distribution : Marks obtained Number of students More than or equal to 0 63 More than or equal to 10 58 More than or equal to 20 55 More than or equal to 30 51 More than or equal to 40 48 More than or equal to 50 42 The frequency of the class 30-40 is (A) 3 (B) 4 (C) 48 (D) 51
(A) 3 Clarification: Imprints Obtained Number of students Cumulative Frequency 0-10 (63 – 58) = 5 5 10-20 (58 – 55) = 3 3 20-30 (55 – 51) =...
The times, in seconds, taken by 150 athletes to run a 110 m hurdle race are tabulated below Class 13.8-14 14-14.2 14.2-14.4 14.4-14.6 14.6-14.8 14.8-15 Frequency 2 4 5 71 48 20 The number of athletes who completed the race in less than 14.6 seconds is : A11 (B) 71 (C) 82 (D) 130
(C) 82 Clarification: The quantity of competitors who finished the race in under 14.6 second= 2 + 4 + 5 + 71 = 82 Subsequently, choice (C) is right
Consider the data : Class 65-85 85-105 105-125 125-145 145-165 165-185 185-205 Frequency 4 5 13 20 14 7 4 The difference of the upper limit of the median class and the lower limit of the modal class is A0 (B) 19 (C) 20 (D) 38
(C) 20 Clarification: Class Frequency Cumulative Frequency 65-85 4 4 85-105 5 9 105-125 13 22 ...
For the following distribution: Marks Number of students Below 10 3 Below 20 12 Below 30 27 Belo w 40 57 Below 50 75 Below 60 80 The modal class is (A)10-20 (B) 20-30 (C) 30-40 (D) 50-60
(C) 30-40 Clarification: Marks Number of students Cumulative Frequency Underneath 10 3=3 3 10-20 (12 – 3) = 9 12 20-30 (27 – 12) = 15 27...
Consider the following frequency distribution: Class 0-05 6-11 12-17 18-23 24-29 Frequency 13 10 15 8 11 The upper limit of the median class is (A)17 (B) 17.5 (C) 18 (D) 18.5
(B) 17.5 Clarification: As per the inquiry, Classes are not constant, henceforth, we make the information nonstop by taking away 0.5 from lower limit and adding 0.5 to furthest reaches of each...
For the following distribution : Class 0-05 5-10 10-15 15-20 20-25 Frequency 10 15 12 20 9 the sum of lower limits of the median class and modal class is (A)15 (B) 25 (C) 30 (D) 35
(B) 25 Clarification: Class Frequency Cumulative Frequency 0-5 10 10 5-10 15 25 10-15 12 37 15-20 ...
The abscissa of the point of intersection of the less than type and of the more than type cumulative frequency curves of a grouped data gives its (A) mean (B) median (C) mode (D) all the three above
(B) Median Clarification: Since, the convergence point of not as much as ogive and more than ogive gives the middle on the abscissa, the abscissa of the mark of convergence of the not as much...
In the formula x = a + h(fiui/fi), for finding the mean of grouped frequency distribution, ui = (A) (xi+a)/h (B) h (xi – a) (C) (xi –a)/h (D) (a – xi)/h
(C) (xi – a)/h Clarification: As indicated by the inquiry, \[x\text{ }=\text{ }a\text{ }+\text{ }h\left( fiui/fi \right),\] Above equation is a stage deviation recipe. In the above recipe, xi is...
If xi’s are the mid points of the class intervals of grouped data, fi’s are the corresponding frequencies and x is the mean, then (fixi – ¯¯¯ x ) is equal to (A)0 (B) –1 (C) 1 (D) 2
(A) 0 Clarification: Mean (x) = Sum of the relative multitude of perceptions/Number of perceptions \[x\text{ }=\text{ }\left( f1x1\text{ }+\text{ }f2x2\text{ }+\text{ }\ldots \text{ }..+\text{ }fnxn...
While computing mean of grouped data, we assume that the frequencies are (A) Evenly distributed over all the classes (B) Centred at the class marks of the classes (C) Centred at the upper limits of the classes (D) Centred at the lower limits of the classes
(B) Centered at the class characteristics of the classes Clarification: In figuring the mean of assembled information, the frequencies are focused at the class signs of the classes. Subsequently,...
Choose the correct answer from the given four options: 1. In the formula For finding the mean of grouped data di’s are deviations from a of (A) Lower limits of the classes (B) Upper limits of the classes (C) Mid points of the classes (D) Frequencies of the class marks
(C) Mid marks of the classes Clarification: We know, \[di\text{ }=\text{ }xi\text{ }\text{ }a\] Where, xi are information and 'a' is the expected to be mean In this way, di are the deviations from...
500 persons are taking a dip into a cuboidal pond which is 80 m long and 50 m broad. What is the rise of water level in the pond, if the average displacement of the water by a person is 0.04m3?
As indicated by the inquiry, Normal dislodging by an individual = 0.04 m3 Normal uprooting by 500 people = 500 × 0.04 = 20 m3 Subsequently, the volume of water brought up in lake = 20 m3 It is...
A solid iron cuboidal block of dimensions 4.4 m × 2.6 m × 1m is recast into a hollow cylindrical pipe of internal radius 30 cm and thickness 5 cm. Find the length of the pipe.
Thinking about cuboidal square Length, l = 4 m Expansiveness, b = 2.6 m Stature, h = 1 m We realize that, Volume of tank = lbh Volume of cuboid = 4.4(2.6)(1) = 11.44 m3 We realize that, The volume...
Water is flowing at the rate of 15 km/h through a pipe of diameter 14 cm into a cuboidal pond which is 50 m long and 44 m wide. In what time will the level of water in pond rise by 21 cm?
Let the time taken by line to fill lake = t hours Water streams 15 km in 60 minutes, in this way, it will stream 15t meters in t hours. We realize that, Volume of cuboidal lake up to tallness 21 cm...