keeping in mind that 120 days is not even a year, since there are 365 days in a year, exluding leap-years, then 120 days is really 120/365 year.
[tex]\bf ~~~~~~ \textit{Simple Interest Earned}
\\\\
I = Prt\qquad
\begin{cases}
I=\textit{interest earned}\\
P=\textit{original amount deposited}\to& \$5000\\
r=rate\to 8.5\%\to \frac{8.5}{100}\to &0.085\\
t=years\to \frac{120}{365}\to &\frac{24}{73}
\end{cases}
\\\\\\
I=(5000)(0.085)\left( \frac{24}{73} \right)\implies I \approx 139.72602739726[/tex]
