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Arranging cardboard circles on a table

Source: XIII Rioplatense Mathematical Olympiad (2004), Level 3

July 26, 2011
geometryrectanglecombinatorics unsolvedcombinatorics

Problem Statement

A collection of cardboard circles, each with a diameter of at most 11, lie on a 5×85\times 8 table without overlapping or overhanging the edge of the table. A cardboard circle of diameter 22 is added to the collection. Prove that this new collection of cardboard circles can be placed on a 7×77\times 7 table without overlapping or overhanging the edge.