Answer
$6480$
Work Step by Step
Formula to calculate the sum of an arithmetic sequence is: $S_n=\dfrac{n}{2}(a_1+a_n)$ ...(1)
Here, $a_1: $ First term and $a_n=$last term
and $a_1: $ First term is 2 and $a_n$:last term is 160
Then, our first (1) equation becomes:
$S_{80}=\dfrac{80}{2}(2+160)\\=40(162)\\=6480$
