# What is the sum of the arithmetic sequence 5, 11, 17 , if there are 24 terms?

Jun 29, 2015

 color(blue)(= 1776

#### Explanation:

$5 , 11 , 17. . .$

The formula for the sum of an arithmetic sequence when ${a}_{1} , d \mathmr{and} n$ are given is:

color(blue)(Sum = (n/2)[2a + (n-1)d]

Here :${a}_{1} = 5 , d = 6 \mathmr{and} n = 24$

$= \left(\frac{24}{2}\right) \left[2 . 5 + \left(24 - 1\right) . 6\right]$

$= 12 . \left[10 + 23 . \left(6\right)\right]$

$= 12. \left[148\right]$
 color(blue)(= 1776