# Alien's fingers

**Number Theory**Level 3

\[\large \frac{5_r}{44_r}=(0.121212\ldots)_r\] Aliens of planet X use their total number of fingers as the base of their number system as we do on earth. Let \(r\) be their number of fingers. Use the equality above, where all the numbers are expressed in base \(r,\) to find the total number of fingers of an alien of planet X.