This is the beginning of 2020 and you hold a bond maturing at the end of 2024 with a coupon of $50, paid at the end of each year. The face value of the bond is $1,000. The current yield to maturity of the bond is 4%.

a. What is the duration of the bond?

b. Suppose that the yield on the bond increased (at the beginning of 2020) from 4% to 4.1%. By what percentage would the price of the bond likely to decline?