The corner points of the feasible region for an L.P.P. are (0, 10), (5, 5), (15, 15) and (0, 20). If the objective function is z = px + qy; p, q > 0, then the condition on p and q so that the maximum of z occurs at (15, 15) and (0, 20) is

q = 3p

Condition of p, q          Z(x, y) = px + qy

so Z(15, 15) = Z(0, 20)

15p + 15q = 20q

15p = 5q

so 3p =q

Option: 3