The societies going against the government will be punished.
Source: Tuymaada 2002, day 1, problem 4. - Authors : V. Dolnikov, D. Karpov.
May 25, 2007
combinatorics proposedcombinatorics
Problem Statement
There are many opposition societies in the city of N.
Each society consists of members. It is known that for every societies there is a person belonging to at least of them.
Prove that the government can arrest people so that at least one member of each society is arrested.Proposed by V.Dolnikov, D.Karpov