Deck of cards labelled with subsets
Source: 239 School Open MO, 2023, Junior league, Problem 8
April 1, 2023
combinatoricsset theory
Problem Statement
Let and be natural numbers, with . In the deck of cards, each card contains a subset of the set consisting of at least , but no more than elements. Each -element set is written exactly on cards. Is it possible to split these cards into stacks so that in each stack all subsets on the cards are different, and any two of them intersect?