Refer to Exercise 11. How many of circuits of Type A and of Type B, should be produced by the manufacturer so as to maximize his profit? Determine the maximum profit.
Refer to Exercise 11. How many of circuits of Type A and of Type B, should be produced by the manufacturer so as to maximize his profit? Determine the maximum profit.

NCERT Exemplar Solutions Class 12 Mathematics Chapter 12 - 12

Solution:

According to the solution of exercise 11, we have Maximize Z=50 x+60 y subject to the constraints

20 x+10 y \leq 2002 x+y \leq 20 \ldots (i)
10 x+20 y \leq 120 x+2 y \leq 12 \ldots (ii)
10 x+30 y \leq 150 x+3 y \leq 15 \ldots (iii)
x \geq 0, y \geq 0 \ldots (iv)

Construct a constrain table for the above

    \[\begin{tabular}{l} Table for (i) \\ \begin{tabular}{|l|l|l|} \hline $\mathrm{x}$ & 10 & 0 \\ \hline $\mathrm{y}$ & 0 & 20 \\ \hline \multicolumn{1}{l}{ Table for (ii) } \\ \hline $\mathrm{x}$ & 12 & 0 \\ \hline $\mathrm{y}$ & 0 & 6 \\ \hline \end{tabular} \\ \hline Table for (iii) \\ \hline \begin{tabular}{|l|l|l|} \hline $\mathrm{x}$ & 15 & 0 \\ \hline y & 0 & 5 \\ \hline \end{tabular} \end{tabular}\]

Next, solving (i) and (ii) we obtain,

\mathrm{x}=28 / 3, \mathrm{v}=4 / 3

Therefore, the corner point is \mathrm{B}(28 / 3,4 / 3).

Solving (ii) and (iii) we obtain,

x=6, y=3 and the corner point is C(6,3)

Lastly, solving (i) and (iii) we obtain,

\mathrm{x}=9, \mathrm{y}=2 \quad (not included in the feasible region)

Here, \mathrm{OABCD} is the feasible region.

As a result, the corner points are \mathrm{O}(0,0), \mathrm{A}(10,0), \mathrm{B}(28 / 3,4 / 3), \mathrm{C}(6,3) and \mathrm{D}(0,5).

Now evaluate the value of Z

    \[\begin{tabular}{|l|l|} \hline Corner points & Corresponding value of $\mathrm{Z}=50 \mathrm{x}+60 \mathrm{y}$ \\ \hline $\mathrm{O}(0,0)$ & $\mathrm{Z}=50(0)+60(0)=0$ \\ \hline $\mathrm{A}(10,0)$ & $\mathrm{Z}=50(10)+60(0)=500$ \\ \hline $\mathrm{B}(28 / 3,4 / 3)$ & $\mathrm{Z}=50(28 / 3)+60(4 / 3)=1400 / 3+240 / 3$ \\ & $=1640 / 3=546.6$ \\ \hline $\mathrm{C}(6,3)$ & $\mathrm{Z}=50(6)+60(3)=480$ \\ \hline $\mathrm{D}(0,5)$ & $\mathrm{Z}=50(0)+60(5)=300$ \end{tabular}\]

So, the maximum profit is Rs 546.6 which is not possible for number of items in fraction. Thus, the maximum profit for the manufacture is Rs 480 at (6,3) i.e. Type \mathrm{A}=6 and Type \mathrm{B}=3.