$1.$ Bob and Angelique Mackenzie bought a property valued at $$84,000$ for $$15,000$ down with

the balance amortized over $20$ years. The terms of the mortgage require equal payments at

the end of each month. Interest on the mortgage is $3\mathrm{.}4\%$ compounded semi$-$annually and

the mortgage is renewable after five years.

a$.$ What is the cost of financing the debt during the first five$-$year term?

b$.$ If the mortgage is renewed for a further five years at $4\mathrm{.}2\%$ compounded semi$-$annually, what will be the size of each monthly payment?