13. You put away $9,000 eighteen years ago. Today, that single investment is now worth $29,932. What is the average annual rate of return you earned on your single investment?

14. Your college student needs a gently-used car, and you believe you can afford $270 a month for a 5-year car loan with no money down. If the interest rate on a used-car loan is 8.5% percent, what is the maximum price for the car you can afford?

15. You contribute $250 per month to your retirement plan, and your employer matches 50% of that amount every month. Assume that you have worked for this employer for 8 years, and the applicable discount rate is 7.55% per year. Given these assumptions, what is this benefit worth to you in today's dollars?