Determine the value of the bond

Question

Problem:

National stee15 year, $1000 par value bonds pay 12 percent annually. The market price is $975.

1. What is the Expected return rate of the 20 year bond paying 8percent if its price is $925?
2. Determine the value of the bond to you given your return rate
3. Should you purchase the bond?

Note: Please provide equation and explain comprehensively and give step by step solution.