Problem #PRU-35415

Problemas Teoría de Números Divisibilidad División con residuos. Aritmética de residuos División con residuo Métodos Principio del palomar Principio del palomar (otro)

Problem

10 natural numbers are written on a blackboard. Prove that it is always possible to choose some of these numbers and write “\(+\)” or “\(-\)” between them so that the resulting algebraic sum is divisible by 1001.