Please explain to me step by step how to solve these questions with the formulas, thank you

37. Assume initially that market interest rates are 7% and the bondholder is receiving a $70 coupon payment per year on a bond with a face value of $1,000. If market interest rates rise to 8%, the bond price: A) falls to $875. B) falls to $800. C) rises to $1,125. D) falls to $700. Assume that market interest rates are 6% and the bondholder receives a $60 coupon payment per year on a bond with a face value of $1,000. If market interest rates fall to 4%, the bond price: A) rises to $1,400. B) rises to $2,000. C) falls to $500. D) rises to $1,500. 38 39. How much is a bond worth i fit pays $55 per year in interest and the market interest rate is 8%? A) $440B) $687.50 C) S787.60 D) $1,250