Original practice · fully worked
Original variant: interest in a declining-payment loan
A six-payment annual loan schedule begins with 2,500 at the end of year 1, and each later payment is 5% smaller than the preceding payment. The loan rate is 6% effective annually. Determine the interest portion of the fifth payment.
- A
181.77 - B
218.56 - C
250.00 - D
305.81 - E
386.12
Answer and calculation
Immediately after payment 4, the present value of payments 5 and 6 is 3642.66. Six percent interest on that balance is 218.56, choice B.
Setup
Setup
Payments 5 and 6 are the only cash flows remaining after payment 4.
P5=2,500(0.95)4 P6=2,500(0.95)5 Model
Model
Value both payments at time 4.
B4=1.06P5+1.062P6=3,642.661 Compute
Compute
The next year's interest is 6% of this post-payment balance.
I5=0.06B4=218.5597 Answer
Answer
The fifth payment contains 218.56 of interest, choice B.
I5=218.56(B)