Shanna wants to buy a house costing $325,000 and has obtained a loan from TD Bank. A minimum down payment of 15% would be required and the bank will provide the difference. Her grandparent have told her that they will cover her down payment.

b. Calculate her monthly mortgage payment, assuming 15% down payment from her grandparents and a mortgage maturity of 25 years.

Answer: Payment is calculated to be $1,543.44

e. Suppose she decides to refinance your mortgage to take advantage of the reduced interest rate. How would her monthly payments change if she could refinance her mortgage at 3.2% (with a 20-year term loan)?

f. Suppose she kept her monthly payments at the original amount found in (b) above at 4.5%, but refinanced the at 3.2%, how long would it take her to pay off the mortgage?

Just need help in part e and f

Thankyou!