Ken and Bob took out $125000 mortgage at 8.75% three years ago. The amortization period was 25 years. What is their monthly payment?

The monthly payment for a mortgage can be calculated using
the formula: M = P [ i*(1 + i)^n] / [ ((1 + i)^n)-1], where M is the monthly payment, i
is the annual rate of interest divided by 12, n is the total number of payments which
would be 12* number of years the mortgage is for and P is the amount
borrowed.

The values given  to us here are P = 125000, i =
.0875 / 12 = 7.29*10^-3, n = 25*12 = 300. I have taken the mortgage to be paid back over
25 years.

The monthly payment is 125000[(0.0875/12)*(1 +
.0875/12)^300)/((1 + .0875/12)^300 - 1)]

calculate using a
calculator

=> M =
$1027.67

Therefore the monthly payment is
$1027.67