10-digit numbers with digits 1-3, written
Source: 1968 Leningrad Math Olympiad - Grade 8.6* asterisk problem
September 1, 2024
number theorycombinatoricsDigits
Problem Statement
All -digit numbers consisting of digits and are written one under the other. Each number has one more digit added to the right. , or , and it turned out that to the number added to the number was assigned , and the number was assigned . It is known that any two numbers that differ in all ten digits have different digits assigned to them. Prove that the assigned column of numbers matches with one of the ten columns written earlier.