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Given that $\frac{S_{1}}{S_{2}}=\frac{3n+8}{7n+5}$, $\frac{S_{1}}{S_{2}}$ is the ratio of sum of two APs to n terms, find the ratio of the 11<sup>th</sup> terms of the two APs.

$\begin{array}{1 1}\frac{72}{151} \\ \frac{71}{152} \\ \frac{152}{72} \\ \frac{151}{71}\end{array}$

1 Answer

Answer : (b) 71/152
Explanation : $\frac{S_{1}}{S_{2}}=\frac{3n+8}{7n+5}$
$We \;require\; the\; ratio \;of\; 11th\; terms \;\frac{A_{1}}{A_{2}}=\frac{a_{1}+10d_{1}}{a_{2}+10d_{2}}$
$We\; get\; n=21$
answered Dec 31, 2013 by yamini.v

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