Calvin has a $4500 debt balance on his Visa card that charges 17.8 percent APR compounded monthly. In 2009 Calvin's minimum monthly payment is 2 percent of his debt balance, which is $90. How many months (round up) will it take Calvin to pay off his credit card if he pays the current minimum of $90 at the end of each month? In 2010, as the result of a federal mandate the minimum monthly payment on credit cards rose to 3 percent. If Calvin made monthly payments of $135 at the end of each month, how long would it take to pay off his credit card?

A. If Calvin made monthly payments at the end of each month, how long would it take to pay off his credit card?

B. If Calvin made monthly payments of $135 at the end of each month, how long would it take him to pay off his credit card?