This morning, you purchased some stereo equipment costing $2,659. You charged this purchase on your credit card. This card charges 16.9 percent interest, compounded monthly. How long will it take you to pay off this purchase if this is the only charge on your credit card and you make monthly payments of $40?

I've found some answer in the course hero. I won't work. When u use the PVAIF factor calculation the highest number should not above 6. How could I repay a $..9@16.9 monthly interest with a $40 monthly payment?