If you can earn 6.5% in simple interest on an investment of $15,000, how much will you have in seven years?

Suppose you borrow $35,000 and you are going to make annual payments of $3,000 for nine years. What interest rate are you paying on the loan?

Another bank will let you borrow the $20,000 for your new car. You can still borrow at 7% per year. If you take the 3-year loan, what are your monthly payment?