SOLUTION: How do you find the sum of the sequences on a problem like this - 1,2,3,4,5,6,7,8,9 ...... 60 ?

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Question 77470: How do you find the sum of the sequences on a problem like this - 1,2,3,4,5,6,7,8,9 ...... 60 ?
Answer by aaaaaaaa(138) About Me  (Show Source):
You can put this solution on YOUR website!
I understand you're asking for the sum of the sequence 1, 2, 3, ..., 60. You can see this is an arithmetic progression and the difference between two terms is 1.
The arithmetic series is given by %28n%28a%5B1%5D+%2B+a%5Bn%5D%29%29%2F2, where n is the number of terms in the sequence, and a%5Bi%5D is the ith term. This formula is easily derivated when you realize that the sum of the first and last terms in the series is the same as the sum of the second and second to last terms, and so forth (60 + 1 = 61, 2 + 59 = 61, etc.)
Substituting for our peculiar sequence gives us %2860%2860%2B1%29%29%2F2+=+%28cross%2860%29%2A61%29%2Fcross%282%29+=+30%2A61+=+1.830