keeping in mind that 10 months is not even a year, since there are 12 months in a year, then 10 months is just 10/12 of a year, or 5/6.
[tex]\bf \qquad \textit{Simple Interest Earned Amount}\\\\
A=P(1+rt)\qquad
\begin{cases}
A=\textit{accumulated amount}\to &\$19500\\
P=\textit{original amount deposited}\\
r=rate\to 7.5\%\to \frac{7.5}{100}\to &0.075\\
t=years\to \frac{10}{12}\to &\frac{5}{6}
\end{cases}
\\\\\\
19500=P\left( 1+0.075\cdot \frac{5}{6} \right)\implies 19500=P(1.0625)
\\\\\\
\cfrac{19500}{1.0625}=P\implies 18352.941176470\approx P[/tex]
