SOLUTION: I hope you can help sove this question; The first term in an arithmetic series is 16 and the last is 60. The sum of the arithmetic series is 342. Find the common difference.

Algebra ->  Sequences-and-series -> SOLUTION: I hope you can help sove this question; The first term in an arithmetic series is 16 and the last is 60. The sum of the arithmetic series is 342. Find the common difference.      Log On


   

Question 359700: I hope you can help sove this question;
The first term in an arithmetic series is 16 and the last is 60. The sum of the arithmetic series is 342. Find the common difference.
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Sum+=+NumberOfTerms%2A%28FirstTerm+%2B+LastTerm%29%2F2
342+=+n+%2A%2816%2B60%29%2F2
342+=+n%2A76%2F2
342+=+38n
9+=+n+
Let the difference between each term be x.
If there are 9 terms, we know that 16+8x = 60 (use one less than 9 )
so
60+-+16+=+8x
44+=+8+x
x+=+5.5