Answer
$\dfrac{116,402}{37,037}$ or, $\dfrac{22}{7}$
Work Step by Step
Consider the series as: $3.\overline{142857}=3+\Sigma_{n=0}^\infty \dfrac{142857}{10^6}\dfrac{1}{(10^6)^n}$ :
Formula to calculate the sum of a geometric series is
$S=\dfrac{a}{1-r}$
Then, we have
$S=3+\dfrac{\dfrac{142857}{10^6}\dfrac{1}{(10^6)^n}}{1-10^6}$
or, $S=\dfrac{116,402}{37,037}$ or, $\dfrac{22}{7}$
