16. You are offered an investment that will pay you $200 in one year, $400 the next year, $600 the next year and $800 at the end of the fourth year. You can earn 12 percent on very similar investments. What is the most you should pay for this one?

17. Your broker calls you and tells you that he has this great investment opportunity. If you invest $100 today, you will receive $40 in one year and $75 in two years. If you require a 15% return on investments of this risk, should you take the investment?

18. You are offered the opportunity to put some money away for retirement. You will receive five annual payments of $25,000 each beginning in 40 years. How much would you be willing to invest today if you desire an interest rate of 12%?