Given:
Face value of the bond = 4,000
coupon rate = 7.75%
bond will mature in 20 years.
7.75% is annual rate.
4,000 * 7.75% = 310 interest to be received annually.
310 * 6/12 = 155 interest to be received semi annually.
310 * 210 years = 6,200 total interest earned in the 20 year term of the bond.