The interest paid would depend on whether you are paying simple interest or compound interest.
For simple interest, the principal remains the same over the 3 years, and interest is charged at 24% per year. The interest in this case is 3*3000*0.24 = $2160
For compound interest, the principal increases every year by the interest charged in the last year. The interest paid in this case is: 3000*(1.24^3 - 1) = $2719.87
The interest paid on the loan would be $2160 in the case of simple interest and $2719.87 in the case of compound interest.