International Competitions 1981

#CompetitionYearsProblemsYears
1International Mathematical Olympiad1959–2025398
2Middle European Mathematical Olympiad2009–2025160
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ProblemSourceTags
International Mathematical Olympiad 1981 Problem 1International Mathematical Olympiad 1981GeometryOptimizationPerpendicularityTriangle
International Mathematical Olympiad 1981 Problem 2International Mathematical Olympiad 1981CombinationsCombinatoricsCounting
International Mathematical Olympiad 1981 Problem 3International Mathematical Olympiad 1981DiophantineNTOptimization
International Mathematical Olympiad 1981 Problem 4International Mathematical Olympiad 1981DivisibilityLCMNT
International Mathematical Olympiad 1981 Problem 5International Mathematical Olympiad 1981CircleCircumcircleGeometryIncircleTriangle
International Mathematical Olympiad 1981 Problem 6International Mathematical Olympiad 1981AlgebraFunctionalRecurrences