The figures are invented. A diagram shows a competitive market for bicycles, with price ($) on the vertical axis and quantity (bicycles per week) on the horizontal axis. The demand curve is a straight line that meets the price axis at $30. The supply curve is a straight line that meets the price axis at $10. The curves cross at a price of $18 and a quantity of 400. (i) Calculate consumer surplus. [2] (ii) Calculate producer surplus. [2]

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