Which of the following is/are solution of the LPP?
\[
\text{Min }Z=12x+9y
\]
Subject to
\[
x+2y\leq 40,\quad 3x+y\geq 30,\quad 4x+3y\geq 60,\quad x,y\geq 0
\]
A. \((15,0)\), B. \((40,0)\), C. \((4,18)\), D. \((6,12)\), E. \((10.5,6)\).
Show Hint
For LPP optimum questions, substitute each given point in the objective function and compare the values.
Concept:
In a Linear Programming Problem, the optimum value is checked at feasible corner points. Here, we calculate \(Z=12x+9y\) at the given feasible points.
Step 1: Calculate \(Z\) at point A \((15,0)\).
\[
Z=12(15)+9(0)=180
\]
Step 2: Calculate \(Z\) at point B \((40,0)\).
\[
Z=12(40)+9(0)=480
\]
Step 3: Calculate \(Z\) at point C \((4,18)\).
\[
Z=12(4)+9(18)
\]
\[
Z=48+162=210
\]
Step 4: Calculate \(Z\) at point D \((6,12)\).
\[
Z=12(6)+9(12)
\]
\[
Z=72+108=180
\]
Step 5: Calculate \(Z\) at point E \((10.5,6)\).
\[
Z=12(10.5)+9(6)
\]
\[
Z=126+54=180
\]
Step 6: Compare values.
Minimum value is:
\[
Z_{\min}=180
\]
This occurs at:
\[
A,\ D,\ E
\]
\[
\therefore \text{Correct Answer is (C)}
\]