16. Suppose you make $4,000 deposits at the end of each year for 3 years. If the interest rate is 4% per year, what is the present value of this ordinary annuity? 17. Suppose you make $4,000 deposits at the beginning of each year for 3 years. If the interest rate is 4% per year, what is the present value of this annuity due? 18. You plan to deposit money into your bank account of $1,500 at the end of period 1, $1,750 at the end of period 2, $2,500 at the end of period 3, $2,750 at the end of period 4, and $3,500 at the end of period 5. The bank offers a 7% interest rate per year for your deposit. What is the future value of this uneven cash flow? 19. You will receive payments of $10,000 at the end of period 1, $20,000 at the end of period 2, $30,000 at the end of period 3, $40,000 at the end of period 4, and $50,000 at the end of period 5. The discount rate is 6% per year. What is the present value of this uneven cash flow? 20. Suppose you have a perpetuity that pays you $2,000 every year. The interest rate is 5%.What is the value of this perpetuity