Digits on a circle
Source: 239 MO 2024 J3
May 22, 2024
number theorycombinatorics
Problem Statement
There are non-zero digits written around a circle. Prove that they can be split into non-empty blocks of consecutive digits so that among the natural numbers formed by the digits in those blocks, at least of them are divisible by (the digits in each block are read in clockwise direction).