Please show within excel

a. What is the duration of a two-year bond that pays an annual coupon of 10 percent and has a current yield to maturity of 12 percent? Use $1,000 as the face value. b. What is the duration of a two-year zero-coupon bond that is yielding 11.5 percent? Use $1,000 as the face value. c. Given these answers, how does duration differ from maturity?