Question: peter can only do one of three options he could...
Peter can only do one of three options. He could go to see a movie (which costs $15 for a ticket) but Peter values at $30. Second, he could go to a friends party (which costs nothing) but Peter values at $20. Finally, he could take an extra shift at work where he will earn benefits of $30, but he has to pay $5 for public transport to get there.
What is Peters opportunity cost of going to the movie? (In this case, you should think of the opportunity cost as including any direct costs incurred, as well as the value of the next-best alternative).