SOLUTION: What is the sum of the first five terms of a geometric series with a1=10 and r=1/5?

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Question 957290: What is the sum of the first five terms of a geometric series with a1=10 and r=1/5?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
S+=+a%2A%281-r%5En%29%2F%281-r%29


S+=+10%2A%281-%281%2F5%29%5E5%29%2F%281-1%2F5%29 Plug in a+=+10, r+=+1%2F5 and n+=+5


S+=+10%2A%281-1%2F3125%29%2F%281-1%2F5%29


S+=+10%2A%283125%2F3125-1%2F3125%29%2F%285%2F5-1%2F5%29


S+=+10%2A%283124%2F3125%29%2F%284%2F5%29


S+=+10%2A%283124%2F3125%29%2A%285%2F4%29


S+=+%2810%2A3124%2A5%29%2F%281%2A3125%2A4%29


S+=+156200%2F12500


S+=+1562%2F125


Final Answer: 1562%2F125

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