Assume that the train ticket price is $100 and 1000 passengers use train per day. 2000 passengers use buses and 5000 passengers use their own car. When the price of train ticket increases to $120; 800 passengers use train, 1800 passengers use bus and 5400 passengers use car. What can you say about the elasticity and cross price elasticity of these three transportation modes? Which modes are complement and which are substitute? Find the cross price elasticities.