Please answer and help me understand. I already know the answers but I would still like to see how to solve it.

2. A 20-year, 8% coupon bond is currently priced to have a yield to maturity of 10 percent. Use the approximation method to answer the following questions: a) Determine the bond's current price. b) If the bond's current price is $800, determine the rate of return on the bond if it is sold 10 years later at $1,200. c) Determine the price at which this bond should be sold 5 years later to earn a holding period yield of 12 percent