Refer to Exercise 12. What will be the minimum cost?
Refer to Exercise 12. What will be the minimum cost?

As per the solution of exercise 12, we have

The objective function for minimum cost is

    \[Z\text{ }=\text{ }400x\text{ }+\text{ }200y\]

Subject to the constrains;

    \[5x\text{ }+\text{ }2y\ge 30\]

….. (i)

    \[2x\text{ }+\text{ }y\le 15\]

….. (ii)

    \[x\le y\]

…. (iii)

and

    \[x\ge 0,\text{ }y\ge 0\]

(non-negative constraints)

Now, let’s construct a constrain table for the above

Next, solving equations (i) and (iii), we get

    \[x\text{ }=\text{ }30/7\text{ }and\text{ }y\text{ }=\text{ }30/7\]

, so the corner point is

    \[A\left( 30/7,\text{ }30/7 \right)\]

On solving equations (ii) and (iii), we get

    \[x\text{ }=\text{ }5\text{ }and\text{ }y\text{ }=\text{ }5\]

, so the corner point is

    \[B(5,5)\]

Here, ABC is the shaded feasible region whose corner points are

    \[A\left( 30/7,\text{ }30/7 \right),\text{ }B\left( 5,\text{ }5 \right)\text{ }and\text{ }C\left( 0,\text{ }15 \right)\]

On evaluating the value of Z, we have

From the table it’s seen that the minimum value is

    \[2571.4\]

Therefore, the required minimum cost is Rs

    \[2571.4\]

at

    \[(30/7,30/7)\]