International Mathematical Olympiad - Wikipedia

The International Mathematical Olympiad (IMO) is an annual six-problem mathematical olympiad for pre-college students, and is the oldest of the International Science Olympiads. The first IMO was held in Romania in 1959. It has since been held annually, except in 1980. More than 100 countries, representing over 90% of the world's population, send teams of up to six students, plus one team