assuming is simple interest, well, 12 months is 1 year, so
[tex]\bf ~~~~~~ \textit{Simple Interest Earned}\\\\I = Prt\qquad\begin{cases}I=\textit{interest earned}\\P=\textit{original amount deposited}\dotfill & \$15000\\r=rate\to 15\%\to \frac{15}{100}\dotfill &0.15\\t=years\dotfill &1\end{cases}\\\\\\I=(15000)(0.15)(1)\implies I=2250[/tex]