Chapter 12 Sequences and Series - 12.4 Find Sums of Infinite Geometric Series - 12.4 Exercises - Skill Practice - Page 823: 11

$S_n=\dfrac{12}{5}$

Here, we have $a_n= a_1 r^{n-1}$ for the Geometric series. First term $a_1= 2$ and Common ratio $r=\dfrac{1}{6}$ The sum of an infinite Geometric Series can be found using: $S_n=\dfrac{a_1}{1-r}$ Thus, $S_n=\dfrac{2}{1-(1/6)}=\dfrac{2 \times 6}{6-1}$ Hence, $S_n=\dfrac{12}{5}$