A Linear Programming Problem is as follows:Maximise / Minimise objective function $Z=2x-y$ $+5$Subject to the constraints$3x+4y \leq 60$$x+3y \leq 30$ $x \geq 0, y \geq 0$If the corner points of the feasible region are $A(0,10), B(12,6), C(20,0)$ and $O(0,0)$, then which of the following is true?