MathDB
2015 marbles in a box, 3 colors at start, one color in the end

Source: INAMO Shortlist 2015 C3

May 14, 2019
ColoringColor problemcombinatorics

Problem Statement

We have 20152015 marbles in a box, where each marble has one color from red, green or blue. At each step, we are allowed to take 22 different colored marbles, then replace it with 22 marbles with the third color. For example, we take one blue marble and one green marble, and we fill with 22 red marbles. Prove that we can always do a series of steps so that all marbles in the box have the same color.