Explanation:
(D) : Given \(z=3 x+5 y\), subject to
\(3 x+2 y \leq 18, x \leq 4, y \leq 6, x \geq 0, y \geq 0\)
We use graphical method to solve,
corner point \(\mathrm{E}\) is \((0,6)\)
corner point \(\mathrm{D}\) is \((0,0)\)
corner point \(\mathrm{C}\) is \((4,0)\)
corner point \(\mathrm{B}\) is \((4,3)\)
corner point \(\mathrm{A}\) is \((2,6)\)

So, The value of \(Z\) corresponding to above point are.
Now, calculate the value of \(z=3 x+5 y\)
\(\mathrm{E}(0,6) \rightarrow 0+30=30\)
\(\mathrm{D}(0,0) \rightarrow 0+0=0\)
\(\mathrm{C}(4,0) \rightarrow 12\)
\(\mathrm{B}(4,3) \rightarrow 12+15=27\)
\(\mathrm{A}(2,6) \rightarrow 6+30=36\)
So, the maximum value is 36