The monthly mortgage payment on your house is $586.81. It is a 30 year mortgage at a quoted rate of 7.8% (compounded semi-annually). Approximately how much did you borrow for your mortgage?

Using the same mortgage amount as in the previous question how much higher or lower would be your monthly payment under a 15-year mortgage as compared to a 25-year mortgage assuming the rate on both mortgages is 7.75% (compounded semi-annually).