finance question please help, thanks in advance

(Annuity payments) Calvin Johnson has a \$4,500 debt balance on his Visa card that charges 17.6 percent APR compounded monthly in 2009 , Calvin's minimum monthly paryment is 2 percent of his debt batance, which is $90. How many months (round up) witl it take Calvin Johnson to pary off his credit cand it he pers the eurrent minimum payment 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 perceot. If Calvin made monthly payments of $135 at the end of each month, how long would it take to pay of his credit card