1. Felix spends 6 hours biking in a road race. The fee to ride costs $40 and he gave up six hours of work at $20/hour. What's his opportunity cost?

2. You are a big baseball fan and were planning to buy a ticket to a game for $15. You value attending the game at $60. A friend offers you a free ticket to a comedy club on the same night. What is your opportunity cost of going to the comedy club?

3. Consider a demand curve for churros. We move along the demand curve when

a) the price of cinnamon increases

b) when a news report comes out saying that churros cause constipation

c) the price of the fryer used to make churros decreases

d) the price of churros changes