you to make if 15 (annual coupons), E6-19. Duration. Calculate the duration of $1,000 face value, 5-year bond that is selling for $1,000. Calculate the duration of a zero coupon, $1,000 face value, 4-year bond. If the only difference between these bonds is their interest rate risk, will the discount rate on the zero coupon bond be greater than or less than 15 percent. Explain. E6-20. Interest Rate Risk. A mortgage-style bond makes equal payments every year. Logically, a 10-year mortgage-style bond has a less interest rate risk than a 10-year coupon bond. Why?