Answer
$15,960$
Work Step by Step
The sequence is arithmetic with common difference d=2,
$a_{1}=14.$
The sum $S_{n}$ of the first $n$ terms of $\left\{a_{n}\right\}$:
$S_{n}=\displaystyle \frac{n}{2}\left[2a_{1}+(n-1)d\right]$
$S_{120}=\displaystyle \frac{120}{2}\left[2(14)+2(120-1)\right]$
$=60(226)=15,960$
