MathDB

2 of 14 with same first and last name - 2011 Portugal (OPM) p4

Source:

May 20, 2024

combinatorics

Problem Statement

In a class of

14

boys, each boy was asked how many classmates had the same first name. and how many colleagues had the same last name as them. The numbers

0, 1, 2, 3, 4, 5

and

6

. Proves that there are two colleagues with the same first name and the same last name