three hands on a clock.
Source: 45th International Tournament of Towns, Senior O-Level P2, Fall 2023
December 16, 2023
combinatorics
Problem Statement
2. There are three hands on a clock. Each of them rotates in a normal direction at some non-zero speed, which can be wrong. In the morning the long and the short hands coincided. Just in three hours after that moment the long and the mid-length hands coincided. After next four hours the short and the mid-length hands coincided. Will it necessarily occur that all three hands will coincide?
Alexandr Yuran