4. You purchase a home movie theatre and sound system for $6,000 and use your credit card for the purchase. You do not make a payment towards this balance for three years. The annual interest rate is 24%, compounded monthly. a) What will be the total amount owing on this debt by the end of the 3 years? b) How much of the total amount owing is considered interest, which has accumulated on this debt over the 3 years?