Answer:
A. payment: $2031.08
B. interest: $203,959.20
Step-by-step explanation:
There are many financial calculators, apps, and spreadsheets that will solve this for you. Here, we will use the amortization formula that would be implemented by one of those.
A.
The monthly payment is given by ...
A = P(r/12)/(1 -(1 +r/12)^(-12t)) . . . loan of P at rate r for t years
If 10% is put down on the house, then amount that needs to be financed will be ...
$315,000 × (1 -10%) = 0.90 × $315,000 = $283,500
For interest rate 6% and a period of 20 years, the monthly payment is ...
A = $283,500(0.06/12)/(1 -(1 +0.06/12)^(-12·20))
A = $283,500(0.005)(1 -(1.005^-240)) ≈ $2,031.08
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B.
The interest is the difference between the amount repaid and the original loan value:
interest = 240 × $2031.08 - 283,500 = $487,459.20 -283,500
interest = $203,959.20
