Suppose that King Kanuta demands that each of his subjects give him 3 coconuts for every coconut that they consume. The king puts all of the coconuts that he collects in a large pile and burns them. The supply of coconuts is given by S(p_s) = 100p_s, where p_s is the price received by suppliers. The demand for coconuts by the king's subjects is given by D(p_d) = 7,650 100p_d, where p_d is the price paid by consumers. In equilibrium, the price received by suppliers will be ?

I can't commute the demand function with supply, notably with the rule of 3