Problem #PRU-21985

Problemas Métodos Métodos algebraicos Conteo de dos maneras Particiones en pares y grupos; biyecciones Principio de casillas Principio de casillas (otro)
 12–13  3.0

Problem

The total age of a group of 7 people is 332 years. Prove that it is possible to choose three members of this group so that the sum of their ages is no less than 142 years.