Answer:
$1516.69 per month less
Step-by-step explanation:
The formula for the monthly payment A on a loan of principal P, annual rate r, for t years is ...
A = P(r/12)/(1 -(1 +r/12)^(-12t))
For the 18.5% loan, the monthly payment is ...
A = 150000(.185/12)/(1 -(1 +.185/12)^(-12·30)) ≈ 2321.92
For the 5% loan, the monthly payment is ...
A = 150000(.05/12)/(1 -(1 +.05/12)^-360) ≈ 805.23
The mortgage at 5% would be $1516.69 less per month.
