A 10-year 15% coupon bond with a face value of $2000 has cash payments identical to zero coupon bonds of $200 each year. 

 

a. Calculate the duration at 15% interest rate. 

b. Calculate the duration when interest rate increase to 20%. 

c. What is the effect on the duration of coupon bond when interest rate increased from 15% to 20%. 

 

Note. Present your answer in a tabular form.