Option 1: make a down payment of $1500 and finance the rest of $2 at 1.9% interest rate, making equal monthly payments for 5 years.

option 2: get a rebate of $1500 to use for your down payment and finance the rest of $2 at 2.9% interest, still making equal monthly payment for 5 years.
you are not sure you can afford either of the monthly payments at the first dealer, so you approach the other dealer to see if she can you. she says that you can have a monthly payment that is $100 less if you make payments for a longer period of time. you don't have to make a down payment, and you will get an interest rate of 2.9%

your task:
determine how long it will take you to pay off your car with this option. use a monthly payment that is $100 lower than the smaller of the two payments you calculated with the previous options.