Today the average undergraduate student is responsible for paying off a $3,500 balance on his/her credit card. Suppose the monthly interest rate is 1.75% (21% APR). How many months will it take to...

Today the average undergraduate student is responsible for paying off a $3,500 balance on his/her credit card. Suppose the monthly interest rate is 1.75% (21% APR). How many months will it take to repay the $3,500 balance, assuming monthly payments of $100 are made and no additional expenses are charged to the credit card? [What is the APR on your personal credit card(s)?]