[tex]\bf ~~~~~~ \textit{Simple Interest Earned}\\\\
I = Prt\qquad
\begin{cases}
I=\textit{interest earned}\\
P=\textit{original amount deposited}\to& \$12000\\
r=rate\to 4.25\%\to \frac{4.25}{100}\to &0.0425\\
t=years\to &5
\end{cases}
\\\\\\
I=12000(0.0425)(5)[/tex]