Question 164048: i realy need a little help with this:
1+2+3+4+5+6...... find the sum of the 20th term?
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! i realy need a little help with this:
1+2+3+4+5+6...... find the sum of the 20th term?
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The 20th term is 20, there is no sum of it.
Do you mean the sum of 20 terms?
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The sum of 20 terms, 1 to 20, is 20 times the average of the terms.
The average is (1+20)/2, or 10.5
20*10.5 = 210
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For n terms, it's n(n+1)/2, only if the 1st term is 1 and the increment is 1.
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