Clark and Lana take a 30-year home mortgage of $122,000 at 7.2%, compounded monthly. They make their regular monthly payments for 5 years, then decide to pay $2000 per month.

(a) Find their regular monthly payment. (Round your answer to the nearest cent.)
$

(b) Find the unpaid balance when they begin paying the $2000. (Round your answer to the nearest cent.)
$

(c) How many payments of $2000 will it take to pay off the loan? Give the answer correct to two decimal places.
monthly payments

(d) Use your answer to part (c) to find how much interest they save by paying the loan this way. (Round your answer to the nearest cent.)
$