The yield to maturity on the issue

United Health Group has bonds outstanding that have four years remaining to maturity,
a coupon interest rate of 8 percent paid annually, and a $1,000 par value.
a. What is the yield to maturity on the issue if the current market price is $829?
b. If the current market price is $1,104?
c. Would you be willing to buy one of these bonds for $829 if you required a 12 percent rate of return on the issue? Explain your answer.