Maths Olympiad Prep

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, 2024

Combinatorics Difficulty 7.0 National Olympiad, round 2 Find the answer Hungary

We fill in an n×nn\times n table with real numbers such that the sum of the numbers in each row and each coloumn equals 1. For which values of KK is the following statement true: if the sum of the absolute values of the negative entries in the table is at most KK, then it's always possible to choose nn positive entries of the table such that each row and each coloumn contains exactly one of the chosen entries.

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