Putnam 2010 B3
Source:
December 6, 2010
Putnamnumber theorygreatest common divisorpigeonhole principlerelatively primecollege contests
Problem Statement
There are 2010 boxes labeled and balls have been distributed among them, for some positive integer You may redistribute the balls by a sequence of moves, each of which consists of choosing an and moving exactly balls from box into any one other box. For which values of is it possible to reach the distribution with exactly balls in each box, regardless of the initial distribution of balls?