The goal is to show that the rate risk in bonds depends on time to maturity and on the size of coupons. Consider the following 4 US Treasury bonds (par value $100) with S/A coupons and 7%YTM (S/A Compounding)

BOND A 5% coupon 2.5Y

BOND B 5% coupon 30Y

BOND C 10% coupon 2.5Y

BOND D 10% coupon 30Y

Calculate the duration of bonds A, B, C and D and explain the differences in their durations.