Recently, you made multiple large purchases on your credit card totaling $17,700. The interest rate on your credit card is 15.2% per year, compounded monthly, and your statement says your minimum payment is $280 per month.

a) How many minimum payments will you need to make in order to pay off your purchases, assuming you cut up your credit card and do not make any additional purchases? (Round your answer up to the nearest number of payments.)

b) How much total interest (in dollars) will you pay by making the minimum monthly payment? (Round your answer to the nearest dollar.)