MathDB

(002) 2

Part of 1980 Tournament Of Towns

Problems(1)

TOT 002 1980 Spring J2 S2 delete a row in NxN array of numbers

Source:

8/16/2019
In a N×NN \times N array of numbers, all rows are different (two rows are said to be different even if they differ only in one entry). Prove that there is a column which can be deleted in such a way that the resulting rows will still be different.
(A Andjans, Riga)
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