It is given in the question that,

Z = 3x + 2y

We have to subject on the following equation:

x +2y ≤ 10, 3x+y ≤ 15, x, y ≥ 0

3x+y ≤ 15

(x, y) = (0, 15), (5, 0)

(x, y) = (0, 5), (10, 0)

We can clearly see that Z is maximum at (4, 3). Hence, maximum value of Z will be 18