Pile of cards
Source: Tournament of Towns, Fall 2002, Junior A Level, P6
May 17, 2014
combinatorics proposedcombinatorics
Problem Statement
There's a large pile of cards. On each card a number from is written. It is known that sum of all numbers on all of the cards is equal to for some . Prove that it is possible to arrange cards into stacks so that sum of numbers written on the cards in each stack is equal to .