anyhow, the common ratio is 2, and the first term is 5 and since there are 5 terms, n = 5,
[tex]\bf \qquad \qquad \textit{sum of a finite geometric sequence}
\\\\
S_n=\sum\limits_{i=1}^{n}\ a_1\cdot r^{i-1}\implies S_n=a_1\left( \cfrac{1-r^n}{1-r} \right)\quad
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
r=\textit{common ratio}\\
----------\\
a_1=5\\
n=5\\
r=2
\end{cases}
\\\\\\
\sum\limits_{i=1}^{5}~5\cdot 2^{i-1}[/tex]
