MathDB

1

Part of 1993 Spain Mathematical Olympiad

Problems(1)

201 people from 5 countries, in each group of 6 at least 2 have same age

Source: Spanish Mathematical Olympiad 1993 P1

8/1/2018
There is a reunion of 201201 people from 55 different countries. It is known that in each group of 66 people, at least two have the same age. Show that there must be at least 55 people with the same country, age and sex.
combinatorics