Hello. I need help with letter (C). The answer for (A) was 3.53%. The answer for (B) was $50.50.

A. Assuming you purchased a $50 face value bond, what rate of return would you earn if you held the bond for 20 years until it doubled in value?

B. If you purchased a $50 face value bond in early 2018 at the then-current interest rate of .10 percent per year, how much would the bond be worth in 2028?

C. In 2028, instead of cashing the bond in for its then-current value, you decide to hold the bond until it doubles in face value in 2038. What rate of return will you earn over the last 10 years?