A company with monopolistie control in the market has fixed weekly costs of $5,000 and per unit costs of $(210+0.05r), where r represents the number of units produced. The weekly demand for a units depends upon the price set by the company. At a price of $300 there will be no demand, but demand increases by one unit for each cent less than $300 the price is set at. (a) Write down the equation for the weekly cost function C(r) and weekly demand function p(x) (price as a function a). (b) What price should the company set to maximise its profit?