[tex]\bf ~~~~~~ \textit{Simple Interest Earned}
\\\\
I = Prt\qquad
\begin{cases}
I=\textit{interest earned}\to &\$1575\\
P=\textit{original amount deposited}\to& \$6000\\
r=rate\to r\%\to \frac{r}{100}\\
t=years\to &7
\end{cases}
\\\\\\
1575=(6000)(r)(7)\implies \cfrac{1575}{(6000)(7)}=r\implies 0.0375=r
\\\\\\
r\%=0.0375\cdot 100\implies r=\stackrel{\%}{3.75}[/tex]