1/ What is a barter economy? Explain why such an approach is difficult for a modern economy.

2/ What is the difference between a pension plan and a defined-contribution plan, such as a 401(k) account?

3/ What gives money value if there is no gold or silver backing the currency?

4/What happens to savings if the real interest rate goes up? What happens to the demand for borrowing?

5/ What are some similarities and differences between cryptocurrency and U.S. dollars that are stored on a popular phone app?