can you please help me with these 3 questions?

You purchased a 7-year annual interest coupon bond one year ago. Its coupon rate was 4.2% and its par value was $1,000. At the time you purchased the bond, the yield to maturity was 4.4%. If you sold the bond after receiving the first interest payment and the bond's yield to maturity had changed to 3.7%, your annual total rate of return of holding the bond for that year would have been %, (Hint: Assume the bond was purchased right after the payment of a coupon and was sold exactly a year later right after the payment of the next coupon.) A) 7.88 B) 7.97 C) 8.06 D) 8.13 Assuming annual compounding, the yield to maturity of a 20 -year zero coupon bond, with a par value of $1,000 and a market price of $492.95, is A) 3.5 B) 3.6 % C) 3.7 D) 3.8 A bond pays annual interest. Its coupon rate is 3.2%. Its value at maturity is $1,000. It matures in four years. Its yield to maturity is presently 2.9%. The duration of this bond is A) 3.82 B) 3.85 C) 3.88 D) 3.91