2024 Portuguese MO Day 2 P5
Source: 2024 Portuguese MO Day 2 P5
March 24, 2024
combinatoricsgraph theory
Problem Statement
In a sport competition, there are teams of two different countries, with teams in each country. Each team plays against two teams from each country, including the one itself belongs to, one game at home, one away. How many different ways can one choose the matches in this competition?