please go over step by step showing the frmula

Rollins, Inc. issued a bond with a face or par value of $1000. The bond has a coupon rate of 8% and makes payments semiannually. The bond has 25 years until maturity, and the annual market interest rate is 6.4%. a) Set up a diagram illustrating the cash flows involved in this bond issue. b) Set up the mathematical equation for the purchase price and find the purchase price of the bond