Difference between revisions of "1983 USAMO Problems/Problem 3"

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[[Category:Olympiad Combinatorics Problems]]

Revision as of 21:31, 17 July 2016

Problem

Each set of a finite family of subsets of a line is a union of two closed intervals. Moreover, any three of the sets of the family have a point in common. Prove that there is a point which is common to at least half the sets of the family.

Solution

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See Also

1983 USAMO (ProblemsResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5
All USAMO Problems and Solutions

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