Essentials of Economics 7th Edition by Gregory Mankiw

Exercise 7

Your aunt is thinking about opening a hardware store. She estimates that it would cost $500,000 per year to rent the location and buy the stock. In addition, she would have to quit her $50,000 per year job as an accountant.
a. Define opportunity cost.
b. What is your aunt's opportunity cost of running a hardware store for a year?
If your aunt thought she could sell $510,000 worth of merchandise in a year, should she open the store? Explain.