Answer
$6$
Work Step by Step
The general formula to find the sum of an infinite Geometric series is given as:
$ S_{n}=\dfrac{a_1}{(1-r)}$
and $ r=\dfrac{a_2}{a_1}=\dfrac{5/6}{5}=\dfrac{1}{6}$
Now, $ S_{n}=\dfrac{a_1}{(1-r)}=\dfrac{5}{1-\dfrac{1}{6}}$
Our answer is: $ S_{n}=\dfrac{5}{5/6}=6$