Use Exact Interest

Short Answer

Use exact interest:
$\begin{array}{|l|l|l|l|l|l|l|}\hline & \text { Interest } & \text { Date } & \text { Date } & & \text { Simple } & \text { Amount } \\ \text { Principal }&\text { Rate } & \text { Borrowed } & \text { Repaid } & \text { Time } & \text { Interest } & \text { Paid Back } \\\hline \$ 24,000 & 12 \% & \text { May } 9 & \text { July } 9 & \text { A } & \text { B } & \text { C } \\\hline\end{array}$