(a) The integers $x$, $x^2$ and $x^3$ begin with the same digit. Does it imply that this digit is $1$? ($2$ points) (b) The same question for the integers $x, x^2, x^3, \cdots, x^{2015}$ ($3$ points) .
Source: Tournament of Towns Spring 2015 Senior A-level
Tags: number theory
(a) The integers $x$, $x^2$ and $x^3$ begin with the same digit. Does it imply that this digit is $1$? ($2$ points) (b) The same question for the integers $x, x^2, x^3, \cdots, x^{2015}$ ($3$ points) .