After Two Years of the First Five-Year Term at 6

Essay

After two years of the first five-year term at 6.7% compounded semi-annually, Dan and Laurel decide to take advantage of the privilege of increasing the payments on their $110,000 mortgage loan by 10%. The monthly payments were originally calculated for a 25-year amortization.
a) How much will the amortization period be shortened?
b) What will be the principal balance at the end of the five-year term?