My pension plan will pay me $17,500 once a year for a 10-year period. The first payment will come in exactly five years. The pension fund wants to immunize its position. a. What is the duration of its obligation to me? The current interest rate is 12.5% per year. b. If the plan uses 5-year and 20-year zero-coupon bonds to construct the immunized position, how much money ought to be placed in each bond? c. What will be the face value of the holdings in each zero?