Cards at a round table
Source: KoMaL A. 827
June 11, 2022
combinatorics
Problem Statement
Let be a given integer. In a deck of cards the cards are of different suites and different values, and for each pair of a suite and a value there is exactly one such card. We shuffle the deck and distribute the cards among players giving each player cards. The players' goal is to choose a way to sit down around a round table so that they will be able to do the following: the first player puts down an arbitrary card, and then each consecutive player puts down a card that has a different suite and different value compared to the previous card that was put down on the table. For which is it possible that the cards were distributed in such a way that the players cannot achieve their goal? (The players work together, and they can see each other's cards.)Proposed by Anett Kocsis, Budapest