Answer
60
Work Step by Step
The values in the sequence are getting smaller and smaller in a geometric sequence. When we divide consecutive terms, we see we have a common ratio of 0.9.
We can use the formula $S_{y}=a/(1-r)$, where a is the first term and r is the ratio between terms.
$S_y=6/(1-0.9)=6/0.1=60$