Answer
$900$
Work Step by Step
$1+3+5+\dots+59$
There is a constant difference, $2$, between terms.
The kth term can be written as $2k-1,$
so the last term is $2(30)-1.$
The terms of the sum
are the first $30$ terms of an arithmetic sequence, $a_{1}=1, d=2.$
Sum of the First $n$ Terms of an arithmetic sequence:
$S_{n}=\displaystyle \frac{n}{2}\left(a_{1}+a_{n}\right)$
$S_{30}=\displaystyle \frac{30}{2}\left(1+59\right)$
$S_{30}=15\cdot 60=900$
