can u please help me in answering this question correctly asap

Question 7 5 pts A zero-coupon bond with a maturity of 10 years has an annual yield of 10%, what is the closest value for its duration? Question 8 5 pts Acme Organic Potato Chip Corp. sold an issue of 12-year $1,000 par bonds for general corporation finance purposes. The bonds pay 4.85% interest, semiannually. Today's required rate of return is 9.7%. How much should these bonds sell for today? Question 9 5 pts Dewey, Cheatham & Howe, a regional brokerage house, has an issue of $1,000 par value bonds with 18 years left until maturity. The coupon rate is 7.7%, with semi-annual payments. If the current price of the bond is $1,175, what is the bond's YTM? (Answer in integer form, such as 51.4, not in decimal form, such as.514 - I'm being VERY clear here, and I won't adjust the answer)