Since you are paying 20% up front, you are paying $45000 up front (.20*225000) which means you are borrowing
225000-45000 = $180,000.
Hopefully, you've learned the formula for figuring out the payment for an amortization problem. It is as follows:
A=P [(1+R/n)nt *R/n] / [(1+R/n)nt -1] A is the amount for each payment, P is the principal, r is the rate, n is the number of payments per year and t is the time in years
So A = 180000 [(1+.065/12)12*30 * .065/12] / [(1+.065/12)360 -1]
A = 180000 [ .037872239/5.991797982]
A = 1137.72
So you will have 360 payments of 1137.72. So over the 30 years, you will pay 360 * 1137.72 = $409,579.20 and you only borrowed 180,000, which means when you subtract them, you'll have 229,579.20 in interest.
Hope this helped.
