The sum of an infinite geometric series with positive terms is $3$ and the sum of the cubes of its terms is $\frac {27}{19}$. Then the common ratio of this series is
$\frac {1}{3}$
$\frac {2}{3}$
$\frac {2}{9}$
$\frac {4}{9}$
If sum of infinite terms of a $G.P.$ is $3$ and sum of squares of its terms is $3$, then its first term and common ratio are
The sum of $3$ numbers in geometric progression is $38$ and their product is $1728$. The middle number is
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
The sum of the first three terms of a $G.P.$ is $S$ and their product is $27 .$ Then all such $S$ lie in
Find the sum of the following series up to n terms:
$6+.66+.666+\ldots$