15. You will be paying $10,000 a year in tuition expenses at the end of the next two years. Bonds currently yield 8%. (LO 11-2) a. What is the present value and duration of your obligation? b. What maturity zero-coupon bond would immunize your obligation? c. Suppose you buy a zero-coupon bond with value and duration equal to your obliga- tion. Now suppose that rates immediately increase to 9%. What happens to your net position, that is, to the difference between the value of the bond and that of your tuition obligation? What if rates fall to 7%