Question: Mr. Logan discover that he can obtain 300 kg/ha of potato if he doesn’t use fertilizer. If he apply a quantity N of fertilizer by hectare, the marginal product of the fertilizer is 1-N/200 (kg of potato / kg of fertilizer).

a) If the potato price is 0.15 $/kg and the price of the fertilizer p [$/kg], witch is the quantity of fertilizer to use to maximize the profit.

b) Write an expression that gives the production by hectare to Mr. Logan, in function of the quantity of fertilizer he uses.