Optimise Z = 3x + 9y subject to the constraints:
x + 3y ≤ 60, x + y ≥ 10, x ≤ y, x ≥ 0, y ≥ 0, then
1
Maximum value of Z occurs at the point (15, 15) only.
2
Maximum value of Z occurs at the point (0, 20) only.
3
Maximum value of Z occurs exactly at two points (15, 15) and (0, 20).
4
Maximum value of Z occurs at all the points on the line segment joining (15, 15) and (0, 20).