a. a pension plan is obligated to make payments of $1 million at the end of each of next 10 years, respectively. Find the duration of the pension funds obligation when the relevant market rate is 10%

b. you would like to immunize the obligation in the above question with 3 year zero coupon bonds and perpetuities. What should be the weight for coupon bonds and perpetuities respectively? (interset rate is still 10%)