how to solve this task?

Problem Consider the following bonds: Bond A Bond B Maturity 15 years 11 years Coupon rate 10% 5% Par Val $1,000 $1,000 Assume the current term structure is flat at 12% p.a. a. In the context of a bond portfolio, what is duration? Why is it important? b. Calculate the duration of each of the bonds above. c. In the context of a bond portfolio, what is convexity? Why is it important? d. Determine a measure of convexity for each of the bonds above. Hint: we'll take our measure of convexity to be the derivative of duration with respect to o, holding P constant i.e. convexity P And the following result may be useful: (n' +2n- 1)a"+2 + (2n2 -2n - 1)."+l - n'a" + + x (1-x)3 e. In conclusion, which bond would you choose