There are 4 sheets in any n among 2000
Source: Chinese Mathematical Olympiad 2000 Problem 6
August 20, 2013
combinatorics unsolvedcombinatoricsSet systems
Problem Statement
A test contains multiple choice questions which have options in each. Suppose each examinee chose one option for each question. There exists a number , such that for any sheets among sheets of answer papers, there are sheets of answer papers such that any two of them have at most questions with the same answers. Find the minimum value of .