# Math - Sum of a Series

Find the sum of the series 23 + 18 + 13 + . . .+ (-82)

A) -590
B) 590
C) -649
D) 649

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3. 👁 73
1. Number of terms
=(23-(-82))/5+1
=22

Sum = (first term + last term)*number of terms / 2
=(23+(-82))*22/2
=-59*11
=-649

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2. Thanks. Mange to figure it out. Got the same answer as you.

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posted by Robo123
3. You're welcome!

How did you do it?

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