European Union
Source: Baltic Way 2004, problem 13
November 20, 2004
combinatorics unsolvedcombinatorics
Problem Statement
The member states of the European Union set up a committee with the following rules:
1) the committee should meet daily;
2) at each meeting, at least one member should be represented;
3) at any two different meetings, a different set of member states should be represented;
4) at meeting, for every , the set of states represented should include at least one state that was represented at the meeting.For how many days can the committee have its meetings?