Problem #PRU-100633

Problemas Métodos Métodos algebraicos Contando de dos maneras

Problem

Several films were nominated for the “Best Math Movie“ award. Each of the 10 judges secretly picked the top movie of their choice. It is known that out of any 4 judges, at least 2 voted for the same film. Prove that there exists a film that was picked by at least 4 judges.