IMO 1988 LL HUN38
In a multiple choice test there were 4 questions and 3 possible
IMO 1988 LL HUN38
Origin: HUN
Problem
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 3 of them there was a question that the three students answered differently. What is the maximal possible number of students tested?