Independent solution

How to solve this Loan Balances and Amortization question

Setup

Setup

Compute the level annual payment and its total over 20 years.

R=1000a200.03R=\frac{1000}{a_{\overline{20}|0.03}}
T1=20RT_1=20R

Model

Model

The second option repays 50 principal each year, so total interest is i times the arithmetic sequence of opening balances.

T2=1000+i(10500)T_2=1000+i(10500)

Compute

Compute

Equating T1 = 1344.3142 to T2 gives i = 3.279182%.

i=1344.31415194100010500=0.0327918240i=\frac{1344.31415194-1000}{10500}=0.0327918240

Answer

Answer

The constant-principal option uses an annual rate of approximately 3.28%, selecting choice C.

i3.28%(C)\boxed{i\approx3.28\%\quad\text{(C)}}