A small country can import a good at a world price of $10 per unit The domestic demand and supply curves are given by the following equations Demand D 400 5P Supply S 20 10P, where D is the quantity demanded, S is the quantity supplied, and P is price a) Derive the import demand curve of the country and determine the level of imports (15 marks) b) Calculate the effects of a perunit tariff of $ 5 levied on imports on consumers, producers, government revenue, and overall national welfare, using the concepts of consumer surplus, producer surplus, and deadweight loss (35 marks) c) Suppose that each unit of production yields a marginal social benefit of $10 and calculate the effect of the tariff on total welfare (1 mark)