Problem #PRU-60877

Problems Number Theory Divisibility Division with remainders. Arithmetic of remainders Euler's theorem Methods Pigeonhole principle Pigeonhole principle (other)
 13–15  3.0

Problem

Prove that if \((m, 10) = 1\), then there is a repeated unit \(E_n\) that is divisible by \(m\). Will there be infinitely many repeated units?