OBM 2008 Problem 1
A positive integer is dapper if at least one of its multiples begins with . For example, is dapper because is a multiple of and begins with . Observe that .
Prove that every positive integer is dapper.
Dataset text AI-MO AoPS. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.
Similar problems
These problems have the most words in common with this statement.