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A G.P consists of 2n terms . If the sum ...

A G.P consists of 2n terms . If the sum of the terms . If the sum of the terms occupying the odd place is `S_(1),` and that of the terms in the even places is `S_(2)`then find the common ratio of the progression

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To solve the problem, we need to find the common ratio of a geometric progression (G.P.) that consists of \(2n\) terms, given the sums of the terms in odd and even places, denoted as \(S_1\) and \(S_2\) respectively. ### Step-by-Step Solution: 1. **Identify the Terms of the G.P.**: The terms of the G.P. can be represented as: \[ a, ar, ar^2, ar^3, \ldots, ar^{2n-1} \] where \(a\) is the first term and \(r\) is the common ratio. 2. **Sum of Terms in Odd Places**: The terms in odd places are: \[ a, ar^2, ar^4, \ldots, ar^{2n-2} \] This forms a G.P. with the first term \(a\) and common ratio \(r^2\). The number of terms is \(n\). The sum \(S_1\) of these terms can be calculated using the formula for the sum of a G.P.: \[ S_1 = a \frac{1 - (r^2)^n}{1 - r^2} = a \frac{1 - r^{2n}}{1 - r^2} \] 3. **Sum of Terms in Even Places**: The terms in even places are: \[ ar, ar^3, ar^5, \ldots, ar^{2n-1} \] This also forms a G.P. with the first term \(ar\) and common ratio \(r^2\). The number of terms is \(n\). The sum \(S_2\) of these terms can be calculated similarly: \[ S_2 = ar \frac{1 - (r^2)^n}{1 - r^2} = ar \frac{1 - r^{2n}}{1 - r^2} \] 4. **Divide \(S_2\) by \(S_1\)**: Now, we can find the ratio \( \frac{S_2}{S_1} \): \[ \frac{S_2}{S_1} = \frac{ar \frac{1 - r^{2n}}{1 - r^2}}{a \frac{1 - r^{2n}}{1 - r^2}} = \frac{ar}{a} = r \] 5. **Conclusion**: Thus, we find that the common ratio \(r\) of the G.P. is given by: \[ r = \frac{S_2}{S_1} \] ### Final Answer: The common ratio of the progression is \( \frac{S_2}{S_1} \).
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