TOT 284 1991 Spring O J4 123+102k
Source:
June 9, 2024
number theoryDigits
Problem Statement
The number is shown on the screen of a computer. Each minute the computer adds to the number on the screen. The computer expert Misha may change the order of digits in the number on the screen whenever he wishes. Can he ensure that no four-digit number ever appears on the screen?(F.L. Nazarov, Leningrad)