SOLUTION: the sum ot infinity of a geometric progression is four times the first term find the common ratio

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Question 761601: the sum ot infinity of a geometric progression is four times the first term find the common ratio
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!
If 'a' is the first term, and 'r' the common ratio of the GP,
the sum to infinity is given by the formula S+=+a%2F%281-r%29
Here since sum is given as 4 times first term, we can write the equation as:
4%2Aa+=+a%2F%281-r%29
Cancelling a from both sides,
4+=+1%2F%281-r%29
i.e.
1+-+r+=+1%2F4
Solving
r+=+3%2F4

:)