The figures are invented. A diagram shows the market for wheat, with price ($ per kg) on the vertical axis and quantity (million kg per year) on the horizontal axis. The equilibrium price is $4 and the quantity is 200. The government sets a minimum price of $5 and buys all the wheat that farmers cannot sell at that price. At $5 the quantity demanded is 180 and the quantity supplied is 250. (i) Calculate the quantity of wheat the government must buy. [1] (ii) Calculate the government's spending on this wheat. [1] (iii) Calculate the change in farmers' total revenue. [2]

HL Paper 3-style calculation (standalone practice; not an IB question).