MathDB
Soviet Union 9

Source: IMO LongList 1959-1966 Problem 52

September 2, 2004
geometrycombinatoricsareacombinatorial geometrydissectionIMO ShortlistIMO Longlist

Problem Statement

A figure with area 11 is cut out of paper. We divide this figure into 1010 parts and color them in 1010 different colors. Now, we turn around the piece of paper, divide the same figure on the other side of the paper in 1010 parts again (in some different way). Show that we can color these new parts in the same 1010 colors again (hereby, different parts should have different colors) such that the sum of the areas of all parts of the figure colored with the same color on both sides is 110.\geq \frac{1}{10}.