Hungarian multiple choice test
Source: IMO LongList 1988, Hungary 3, Problem 33 of ILL
October 22, 2005
geometryrectanglecombinatorics unsolvedcombinatorics
Problem Statement
In a multiple choice test there were 4 questions and 3 possible answers for each question. A group of students was tested and it turned out that for any three of them there was a question which the three students answered differently. What is the maximum number of students tested?