The Fix family bought a house for $210,000. They paid $42,000 down and took out a 30-year mortgage for the balance at 3.75%.

a.) Find the monthly payment

b.) How much of the first payment is interest?

c.) After 15 years, the family sold their house for $255,000. Estimate the current mortgage balance at the time of the sale.

d.) Find the amount of money they received from the sale after paying off the mortgage.