a) A local cinemaincreasesits ticket price from $20 to $24. The quantity demanded of tickets soondecreasesfrom 1600 to 1200 tickets per week. What is the price elasticity of demand? Use the percentage change method. Briefly explain whether this price increase will increase or decrease total revenue. ( E_d= %Q / %P ).

b) When the local cinema increased the ticket prices from $20 to $24, the nearby popcorn seller hada 20% decreasein sales. What isthe cross-price elasticity of demand and are these substitute or complementary goods?