Maths

Determine whether or not the definition of * given below gives a binary operation. In the event that * is not a binary operation give justification of this.(v) On Z+ define * by a * b = a (vi) On R, define * by a * b = a + 4b2

(v) Given on Z+ define * by a * b = a Let \[\begin{array}{*{35}{l}} a,\text{ }b\text{ }\in \text{ }{{Z}^{+}}  \\ \Rightarrow \text{ }a\text{ }\in \text{ }{{Z}^{+}}  \\ \Rightarrow \text{ }a\text{...

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Check whether the following pair of statements is a negation of each other. Give reasons for your answer. (i) a + b = b + a is true for every real number a and b. (ii) There exist real numbers a and b for which a + b = b + a.

Answer: The negation of the statement: p: a + b = b + a is a true for every real number a and b. ~p: There exist real numbers are ‘a’ and ‘b’ for which a+b ≠ b+a. The statement is not the negation...

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Are the following pairs of statements are a negation of each other: (i) The number x is not a rational number. The number x is not an irrational number. (ii) The number x is not a rational number. The number x is an irrational number.

Answers: (i) “The number x is an irrational number.” The statement “The number x is not a rational number.” It is a negation of the first statement. (ii) “The number x is an irrational number.” The...

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Write the component statements of the following compound statements and check whether the compound statement is true or false: (i) Square of an integer is positive or negative. (ii) x = 2 and x = 3 are the roots of the equation 3×2 – x – 10 = 0.

Answers: (i) The components of the compound statement are: P: Square of an integer is positive. Q: Square of an integer is negative. Both P and Q are true. The compound statement is True. (ii) The...

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Write the component statements of the following compound statements and check whether the compound statement is true or false: (i) To enter into a public library children need an identification card from the school or a letter from the school authorities. (ii) All rational numbers are real and all real numbers are not complex.

Answers: (i) The components of the compound statement are: P: To get into a public library children need an identity card. Q: To get into a public library children need a letter from the school...

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For each of the following statements, determine whether an inclusive “OR” o exclusive “OR” is used. Give reasons for your answer. (i) A lady gives birth to a baby boy or a baby girl. (ii) To apply for a driving license, you should have a ration card or a passport.

Answers: (i) “A lady gives birth to a baby boy or a baby girl.” An exclusive “OR” is used because a lady cannot give birth to a baby who is both a boy and a girl. (ii) “To apply for a driving...

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For each of the following statements, determine whether an inclusive “OR” o exclusive “OR” is used. Give reasons for your answer. (i) Students can take Hindi or Sanskrit as their third language. (ii) To entry a country, you need a passport or a voter registration card.

Answers: (i) “Students can take Hindi or Sanskrit as their third language.” An exclusive “OR” is used because a student cannot take both Hindi and Sanskrit as the third language. (ii) “To entry a...

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Rewrite each of the following statements in the form “p if and only is q.” (i) r: For you to get an A grade, it is necessary and sufficient that you do all the homework you regularly. (ii) s: If a tumbler is half empty, then it is half full, and if a tumbler is half full, then it is half empty.

Answers: (i) In the form “p if and only is q.” You get an A grade if and only if you do all the homework regularly. (ii) In the form “p if and only is q.” A tumbler is half empty if and only if it...

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Rewrite each of the following statements in the form “p if and only is q.” (i) p: If you watch television, then your mind is free, and if your mind is free, then you watch television. (ii) q: If a quadrilateral is equiangular, then it is a rectangle, and if a quadrilateral is a rectangle, then it is equiangular.

Answers: (i) In the form “p if and only is q.” You watch television if and only if your mind is free. (ii) In the form “p if and only is q.” A quadrilateral is a rectangle if and only if it is...

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Determine whether the argument used to check the validity of the following statement is correct: p: “If x2 is irrational, then x is rational.” The statement is true because the number x2 = π2 is irrational, therefore x = π is irrational.

Answer: Argument Used: x2 = π2 is irrational So, x = π is irrational. p: “If x2 is irrational, then x is rational.” Consider, An irrational number given by x = √k  [k is a rational number] Squaring...

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Which of the following statements are true and which are false? In each case give a valid reason for saying so (i) r: Circle is a particular case of an ellipse. (ii) s: If x and y are integers such that x > y, then – x < – y.

Answers: (i) r: Circle is a particular case of an ellipse. A circle can be an ellipse in a particular case when the circle has equal axes. The statement is true. (ii) s: If x and y are integers such...

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Which of the following statements are true and which are false? In each case give a valid reason for saying so (i) p: Each radius of a circle is a chord of the circle. (ii) q: The centre of a circle bisect each chord of the circle.

Answers: (i) p: Each radius of a circle is a chord of the circle. The Radius of the circle is not it chord. The statement is False. (ii) q: The centre of a circle bisect each chord of the circle. A...

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Check whether the following statement is true or not: (i) p: If x and y are odd integers, then x + y is an even integer. (ii) q : if x, y are integer such that xy is even, then at least one of x and y is an even integer.

Answers: (i) p: If x and y are odd integers, then x + y is an even integer. Conisder, p: x and y are odd integers. q: x + y is an even integer If p, then q. Let p be true. [x and y are odd integers]...

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Find the coordinates of the vertices of a triangle, the equations of whose sides are: (i) x + y – 4 = 0, 2x – y + 3 0 and x – 3y + 2 = 0 (ii) y (t1 + t2) = 2x + 2at1t2, y (t2 + t3) = 2x + 2at2t3 and, y(t3 + t1) = 2x + 2at1t3.

\[\left( \mathbf{i} \right)~x\text{ }+\text{ }y\text{ }\text{ }4\text{ }=\text{ }0,\text{ }2x\text{ }\text{ }y\text{ }+\text{ }3\text{ }0\] and \[x\text{ }\text{ }3y\text{ }+\text{ }2\text{ }=\text{...

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A piece of equipment cost a certain factory 600,000 . If it depreciates in value 15 \% the first, 13.5 \% the next year, 12 \% the third year, and so on. What will be its value at the end of 10 years, all percentages applying to the original cost?

Solution: Given that a piece of equipment cost a certain factory is ₹ 600,000 We have to find the value of the equipment at the end of 10 years. The price of equipment depreciates $15 \%, 13.5 \%,...

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A man is employed to count ₹ 10710 . He counts at the rate of 180 per minute for half an hour. After this he counts at the rate of ₹3 less every minute than the preceding minute. Find the time taken by him to count the entire amount.

Solution: Given that the amount to be counted is ₹ 10710 We have to find the time taken by man to count the entire amount. He counts the amount at the rate of ₹ 180 per minute for 30 minutes. Amount...

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There are 25 trees at equal distances of 5 meters in a line with a well, the distance of well from the nearest tree being 10 meters. A gardener waters all the trees separately starting from the well and he returns to the well after watering each tree to get water for the next. Find the total distance the gardener will cover in order to water all the trees.

Solution: It is given that total number of trees are 25 and the distance between two adjacent trees are 5 meters To find the total distance the gardener will cover. As given the gardener is coming...

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A manufacturer of the radio sets produced 600 units in the third year and 700 units in the seventh year. Assuming that the product increases uniformly by a fixed number every year, find
(і) the product in the 10th year.

Solution: Given that, In the third and seventh year 600 and 700 radio sets units are produced, respectively. $a_3 = 600$ and $a_7 = 700$ (i) The product in the $10^{\text {th }}$ year. Find the...

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A manufacturer of the radio sets produced 600 units in the third year and 700 units in the seventh year. Assuming that the product increases uniformly by a fixed number every year, find
(і) the production in the first year
(іі) the total product in the 7 years and

Solution: Given that, In the third and seventh year 600 and 700 radio sets units are produced, respectively. $a_3 = 600$ and $a_7 = 700$ (і) The production in the first year Find the production in...

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A man arranges to pay off a debt of ₹ 3600 by 40 annual instalments which form an arithmetic series. When 30 of the instalments are paid, he dies leaving one-third of the debt unpaid, find the value of the instalment.

Solution: As per the question: There are 40 annual instalments that form an arithmetic series. Let '$a$' be the first instalment $S_{40}=3600, n=40$ Using the formula, $\begin{array}{l} S_{n}=n /...

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