If $x,\,2x + 2,\,3x + 3,$are in $G.P.$, then the fourth term is
$27$
$- 27$
$13.5$
$- 13.5$
Given a $G.P.$ with $a=729$ and $7^{\text {th }}$ term $64,$ determine $S_{7}$
If ${G_1}$ and ${G_2}$ are two geometric means and $A$ the arithmetic mean inserted between two numbers, then the value of $\frac{{G_1^2}}{{{G_2}}} + \frac{{G_2^2}}{{{G_1}}}$is
The sum of the series $3 + 33 + 333 + ... + n$ terms is
The number $111..............1$ ($91$ times) is a
If the sum of an infinite $G.P.$ and the sum of square of its terms is $3$, then the common ratio of the first series is