Answer
$\frac{2}{3}$
Work Step by Step
An infinite geometric series has a sum if and only if $|r|\lt1$, where $r$ is the common ratio. If it exists, then it equals $\frac{a_1}{1-r}$ where $a_1$ is the first term.
Here $|-0.5|\lt1$.
Hence the sum: $\dfrac{1}{1-(-0.5)}=\frac{2}{3}$
