Mary has $6,000 on her credit card, which charges an APR of 22% and Mike has a credit card that charges an APR of 15% and he carries a balance of $4,000. They pay the minimum payment each month on their credit cards, the amount specified on the credit card statements.

Question: How many years would it take to pay off their credit cards if they each were to pay $250 each month and not charge anything further on it?