Amy Phillips needs to borrow $20,000 to purchase a new car. She can get a 3 year loan from her bank with an interest rate of 7% (compounded monthly). Calculate Amy's monthly payment.

Also how much interest (in dollars) will Amy pay over the life of the loan?

Lastly, if Amy got a 5 year loan instead of a 3 year loan, how much interest (in dollars) would she pay over the life of the loan?

Answer using formulas - no calculator or excel. Please show work. Please also tell what formula you will be using