1. Suppose that you are considering purchasing a ticket to go to a concert with some friends. What is your opportunity cost? (Hint: What would you do with the time and money?
2. Suppose that I already have purchased a ticket for $50 to a sold-out concert. I could turn it back into the box office and get a refund, or I could sell it for $120 on eBay or Craigslist to someone who does not have a ticket. What is my opportunity cost of attending the concert? (Hint: What do I actually give up with this decision?)
3. Suppose that you have purchased the ticket for $50. There is no scalping market. (People can buy tickets at the box office and it is illegal to buy or sell tickets from or to anyone else.) Also, suppose that the box office will not refund the ticket price once the ticket has been purchased. What is your opportunity cost of attending the concert in this case?

The ideal answer to each question is about half page.