Hungary-Israel Binational 1999\6
Source: Maximal number of examinees
October 30, 2008
combinatorics unsolvedcombinatorics
Problem Statement
In a multiple-choice test, there are 4 problems, each having 3 possible answers.
In some group of examinees, it turned out that for every 3 of them, there was a question that each of them gave a different answer to. What is the maximal number of examinees in this group?