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Grade 11Algebra

In a GP the ratio of the sum of the first eleven terms to the sum of last eleven terms is 1/8 and the rati of the sum of all the terms without the first nine to the sum of all the terms without the last nine terms is 2. Find the number of terms in the GP.

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Profile image of Abhishek jha
7 Years agoGrade 11
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1 Answer

Profile image of Vijay
7 Years ago
From first condition we have (r) ^(n-11)=8 and from second condition we have r^9=2 . Solving we will have n=38.