Solve

Short Answer

Solve:
$$\begin{array} { | l | l | l | l | } \hline \text { Principal } & \text { Rate } & \text { Time } & \begin{array} { l } \text { Simple } \\\text { Interest }\end{array} \\\hline \$ 6,000 & ? & 6 \mathrm { mos } & \$ 330 \\\hline\end{array}$$