Find the sum of all the term in arithmetic progression 180,175,170......25?

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Answer 1 · 2018-02-06T08:46:16

#3280#

This arithmetic progression has common difference #-5#

The number of terms is:

#(180-25)/5+1 = 32#

The average term is the same as the average of the first and last terms, namely:

#(180+25)/2 = 205/2#

So the sum of the series is:

#32 * 205/2 = 16*205 = 3280#