must show work without excel

Shert owes 55,500 en ber credit cart. The card has an APR of 14.9 pereet. Sherri has decided not to charge any additional purchases because she wants to get this debt paid in full. A) How munh loeger will it take her to pay ofr this balance if she makes menthly payments of $70 rather than $80 ? B) What is ber total iakrest paywent in both cases