For an arithmetic sequence $\left\{ a _ { n } \right\}$ with first term $- 5$ and common difference 2, what is the value of $\sum _ { k = 11 } ^ { 20 } a _ { k }$? [3 points] (1) 260 (2) 255 (3) 250 (4) 245 (5) 240
For an arithmetic sequence $\left\{ a _ { n } \right\}$ with first term $- 5$ and common difference 2, what is the value of $\sum _ { k = 11 } ^ { 20 } a _ { k }$? [3 points]\\
(1) 260\\
(2) 255\\
(3) 250\\
(4) 245\\
(5) 240