Compute the Missing Amount for Each of the Following Notes

Essay

Compute the missing amount for each of the following notes: $\begin{array} { c c c c c } & \text { Principal } & \text { Annual Interest Rate } & \text { Time } & \text { Total Interest } \\\hline \text { (a) } & \$ 40,000 & 10 \% & 2.5 \text { years } & ? \\\hline \text { (b) } & \$ 120,000 & ? & 9 \text { months } & \$ 7,200 \\\hline \text { (c) } & ? & 10 \% & 90 \text { days } & \$ 1,500 \\\hline \text { (d) } & \$ 40,000 & 9 \% & ? & \$ 1,200 \\\hline\end{array}$