3
Part of 2000 China National Olympiad
Problems(2)
Tennis Club hosts a series of doubles matches
Source: Chinese Mathematical Olympiad 2000 Problem 3
8/19/2013
A table tennis club hosts a series of doubles matches following several rules:
(i) each player belongs to two pairs at most;
(ii) every two distinct pairs play one game against each other at most;
(iii) players in the same pair do not play against each other when they pair with others respectively.
Every player plays a certain number of games in this series. All these distinct numbers make up a set called the “set of games”. Consider a set of positive integers such that every element in is divisible by . Determine the minimum number of players needed to participate in this series so that a schedule for which the corresponding set of games is equal to set exists.
combinatorics unsolvedcombinatorics
There are 4 sheets in any n among 2000
Source: Chinese Mathematical Olympiad 2000 Problem 6
8/20/2013
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 .
combinatorics unsolvedcombinatoricsSet systems