How does the existence of black market work against the intended purpose of rationing

Suppose your rich uncle gave you $50,000, which you plan to use for graduate school. you will make the investment now, you expect to earn an annual return of 6%, and you will make 4 equal annual withdrawals, beginning 1 year from today. under these conditions, how large would each withdrawal be so there would be no funds remaining in the account after the 4th withdraw?

Taking commercial paper means the holder acts honestly

Arnold rossiter is a 40-year-old employee of the barrington company who will retire at age 60 and expects to live to age 75. the firm has promised a retirement income of $20,000 at the end of each year following retirement until death. the firm's pension fund is expected to earn 7 percent annually on its assets and the firm uses 7% to discount pension benefits. what is barrington's annual pension contribution to the nearest dollar for mr. rossiter? (assume certainty and end-of-year cash flows.)