A car loan company states. "You only pay $.31 a day for each $500.00 borrowed." If you borrow $1,431 for 151 days, what amount will you repay. and what annual interest rate is the company actually charging" (Assume a 360-day year)

The amount you will repay can be solved by:

Amount to be repaid = ($ 1, 431 borrowed) ($ 0.31 per day / $ 500 borrowed) 151 days

Amount to be repaid = $ 133.97

The annual interest rate is:

1431 + 133.97 = 1431 (1 + i) ^ 151 (1/360)

Solve for i

i = 0.2378 or 23.78 % per year