1003085205

SubArea: 
Arithmetic sequences
Level: 
B
Project ID: 
1003085205
Accepted: 
1
Clonable: 
0
Easy: 
0
Find the sum of the $10$th up to $20$th term of an arithmetic sequence given by: $a_{n+1}=a_n+2$ for all $n\in\mathbb{N}$ and $a_1=-4$.
$264$
$240$
$480$
$-320$
$-352$