The sum of the infinite G.P is 15,  Sum of squares of 3 terms of the g.p is 45. Find the series.

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The sum of the infinite G.P is 15 and Sum of squares of these terms is 45. Find the series. 


Let a be the first term and r be the common ratio of the infinite geometric series.

Sum of infinite g.p. = 15

Also, sum of squares = 45

On dividing the square of (1) by (2), we get

On putting value of r in (1), we get a = 5

Hence, the required series is:

  • 28
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