Answer
$=\dfrac {8}{9}$
Work Step by Step
$0.\overline {8}=0.8888\ldots =\dfrac {8}{10}+\dfrac {8}{10^{2}}+\dfrac {8}{10^{3}}...=\dfrac {a_{1}}{1-r};a_{1}=\dfrac {8}{10};r=\dfrac {1}{10}\Rightarrow 0.\overline {8}=\dfrac {\dfrac {8}{10}}{1-\dfrac {1}{10}}=\dfrac {8}{9}$
