6.a. Annual interest. Tommy is borrowing $12,000 on a 10-year, 18% annual interest loan. How much interest will Tommy have paid over the entire course of the loan when it is finally repaid assuming interest is compounded annually, and payments are paid annually?

6.b. Monthly interest. Assuming Tommy made the same borrowing, but the interest was calculated monthly and payments were made monthly, how much interest will Tommy have paid over the entire course of the loan?