50 cards shuffled
Source: Canadian Mathematical Olympiad - 1980 - Problem 2.
May 16, 2011
combinatorics proposedcombinatorics
Problem Statement
The numbers from to are printed on cards. The cards are shuffled and then laid out face up in rows of cards each. The cards in each row are rearranged to make them increase from left to right. The cards in each column are then rearranged to make them increase from top to bottom. In the final arrangement, do the cards in the rows still increase from left to right?