Question
For the G.P.

If $a=\frac{2}{3}, t_6=162$, find $r$.

Answer

Given, $a=\frac{2}{3}, t_6=162$

$\begin{array}{ll}\therefore & t_n=a r^{n-1} \\ \therefore & t_6=\left(\frac{2}{3}\right)\left(r^{6-1}\right) \\ \therefore & 162=\frac{2}{3} r^5 \\ \therefore & r^5=162 \times \frac{3}{2} \\ \therefore & r^5=3^5 \\ \therefore & r=3\end{array}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free