Interest Rebate - Rule Of 78'S - HP 12c Solutions Handbook

Interest Rebate - Rule of 78's

This procedure finds the unearned interest rebate, as well as the
remaining principal balance due for a prepaid consumer loan using the
Rule of 78's. The known values are the current installment number, the
total number of installments for which the loan was written, and the total
finance charge (amount of interest). The information is entered as follows:
1. Key in number of months in the loan and press
2. Key in payment number when prepayment occurs and press
1 .
3. Key in total finance charge and press
4. Key in periodic payment amount and press
obtain the amount of principal outstanding.
Example 1: A 30 month $1000 loan having a finance charge of $180, is
being repaid at $39.33 per month. What is the rebate and balance due
after the 25th regular payment?
Keystrokes
30 1
25 2
1 180
1
1
2
39.33 2
The following HP-12C program can be used to evaluate the previous example.
KEYSTROKES
CLEAR
-651.10
12.39
2 to obtain the unearned interest (rebate).
Display
5.81
190.84
27
Total finance charge.
APR.
1
2
Rebate.
Outstanding principal.
DISPLAY
00-
1.
to
2
1