Independent solution

How to solve this Loan Balances and Amortization question

Setup

Setup

The monthly rate is 9% divided by 12, and the first remaining payment is the original payment reduced forty times.

j=0.09/12j=0.09/12
P41=1000(0.98)40P_{41}=1000(0.98)^{40}

Model

Model

The balance immediately after payment 40 is the present value of payments 41 through 60.

B40=k=1201000(0.98)39+k(1.0075)kB_{40}=\sum_{k=1}^{20}\frac{1000(0.98)^{39+k}}{(1.0075)^k}

Compute

Compute

Evaluating the finite geometric present value gives 6889.114798.

B40=6889.11479801B_{40}=6889.11479801

Answer

Answer

The outstanding balance is approximately 6,889, selecting choice A.

B406889(A)\boxed{B_{40}\approx6889\quad\text{(A)}}