1. ## interest rate problem

I'm going wrong when I try to determine the interest rate.

terms: 0.31 cents per day for each 500.00 borrowed
principal 2623.00
time: 173 days (360 day year)

what is the total repayment amount and the interest rate?

2623/500 = 5.246

5.246 * 0.31 = 1.62626

1.62626 * 173 = 281.34

281.34 + 2623 = 2904.34 total repayment

I = Prt

t = 173/360 = .48

281.34 = r(281.34)(.48)

r = (281.34 * 48)/2623

r = ?

the answer is suppose to be: 22.3198 interest rate

2. I = Prt

t = 173/360 = .48

281.34 = r(281.34)(.48)

r = (281.34 * 48)/2623
You appear to have put some information in the incorrect place

$\displaystyle I=Prt \iff 281.34=(2623)\cdot r \cdot (.48) \iff r=\frac{281.34}{(.48)(2623)}\approx 0.2231859$

3. Hi hansfordmc,
The interest is 0.31 dollars per day not cents per day. Figure the daily interest rate against 500 d.The annual rate is daily rate times 360.To get total interest paid apply the daily rate to the loan amount times 173 days.