September 2008
Consider a 13x13 checkerboard. It can be partitioned into a collection of smaller square checkerboards in various ways. For example into 169 1x1 checkerboards or into 1 12x12 and 25 1x1 checkerboards. What is the minimum number of smaller square checkerboards that a 13x13 checkerboard can be partitioned into? Show how this can be done. Note we are not asking for (and will not supply) a proof of minimality.
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Challenge:
09/01/2008 @ 03:00 AM EST
Solution:
10/01/2008 @ 03:00 AM EST
List Updated:
10/07/2008 @ 08:00 AM EST
People who answered correctly:
Dan Dima (09.04.2008 @02:43 PM EDT)
V Balakrishnan (09.04.2008 @03:28 PM EDT)
Albert Stadler (09.04.2008 @02:15 PM EDT)
Bojan Basic (09.04.2008 @02:35 PM EDT)
Alan O'Donnell (09.04.2008 @01:59 PM EDT)
Andreas Eisele (09.04.2008 @05:32 PM EDT)
Raul Blazquez (09.04.2008 @06:37 PM EDT)
Sangita Ukil & Abhisek Ukil (09.04.2008 @08:14 PM EDT)
Gale Greenlee (09.05.2008 @12:17 AM EDT)
Zhou Guang (09.05.2008 @02:19 AM EDT)
Dan Colestock (09.05.2008 @02:32 AM EDT)
Andreas Gruen (09.05.2008 @10:55 AM EDT)
Harald Boegeholz (09.05.2008 @11:15 AM EDT)
Gary M. Gerken (09.05.2008 @11:31 AM EDT)
Henry Bottomley (09.05.2008 @11:38 AM EDT)
Michael Schaaf (09.05.2008 @01:21 PM EDT)
Farid Lian (09.05.2008 @04:36 PM EDT)
John Tromp and Alvaro Begue (09.05.2008 @04:41 PM EDT)
Arthur Breitman (09.05.2008 @07:07 PM EDT)
Lego Haryanto (09.05.2008 @08:47 PM EDT)
David Barr (09.06.2008 @07:36 AM EDT)
Fred Schalekamp (09.06.2008 @09:57 AM EDT)
Krunoslav Kovac (09.06.2008 @12:01 AM EDT)
Mathias Schenker (09.06.2008 @03:25 PM EDT)
Simon Frettloeh (09.06.2008 @04:47 PM EDT)
Maris van Sprang (09.06.2008 @04:47 PM EDT)
Arno Candel (09.06.2008 @06:24 PM EDT)
Michael Liepelt (09.07.2008 @11:56 AM EDT)
Joseph DeVincentis (09.07.2008 @08:04 PM EDT)
Andreas Stiller (09.07.2008 @08:20 PM EDT)
Radu Borza (09.07.2008 @12:44 PM EDT)
Karthik Kumar (09.08.2008 @06:12 AM EDT)
Gergely Pataki (09.08.2008 @04:26 PM EDT)
Reiner Martin (09.08.2008 @06:01 PM EDT)
Frank Vernaillen (09.08.2008 @06:29 PM EDT)
Stephen Merriman (09.08.2008 @07:37 AM EDT)
Daniel Hsu (09.08.2007 @07:58 PM EDT)
Jack Kennedy (09.08.2008 @12:54 PM EDT)
L J Zigerall Jr (09.09.2008 @02:10 AM EDT)
Aleksandar Damnjanovic (09.09.2008 @12:08 AM EDT)
Eugene Vasilchenko (09.09.2008 @05:26 PM EDT)
Anthony P Jones (09.10.2008 @09:43 PM EDT)
Daniel Bitin (09.10.2008 @12:36 PM EDT)
Amos Guler (09.11.2008 @01:19 PM EDT)
Luke Pebody (9.11.2008 @05:57 PM EDT)
Joaquim Carrapa (9.11.2008 @06:57 PM EDT)
Raphael Finkel (9.12.2008 @06:22 AM EDT)
Chuck Grant (9.12.2008 @10:32 AM EDT)
Mate Bartalos (9.12.2008 @05:30 AM EDT)
Cobus de Waal (9.12.2008 @06:09 AM EDT)
Alex Wagner (9.12.2008 @08:41 PM EDT)
Sinisa Popovic (9.13.2008 @09:08 AM EDT)
George McCarthy (9.13.2008 @09:09 AM EDT)
Catalin Buzoiu (9.13.2008 @05:46 PM EDT)
Jesse Kolman (9.13.2008 @07:25 PM EDT)
Rani Hod (9.14.2008 @09:56 AM EDT)
Christian Pape (9.14.2008 @01:23 PM EDT)
Nicolas Wu (9.15.2008 @01:18 PM EDT)
Karthik Kalyanam (9.15.2008 @11:51 PM EDT)
Victor Chang (9.16.2008 @02:54 AM EDT)
Dave Parashar (9.16.2008 @08:29 AM EDT)
Fabio Filatrella (9.16.2008 @10:57 AM EDT)
Andrew Rochon (9.16.2008 @09:37 PM EDT)
Benjamin Bachmann (9.17.2008 @08:54 AM EDT)
Kalle Matias Leppele (9.18.2008 @09:27 AM EDT)
Donald T. Dodson (9.18.2008 @03:25 PM EDT)
Ioan Marius Popdan (9.19.2008 @10:32 AM EDT)
Jiri Navratil (9.19.2008 @01:57 PM EDT)
Nyles Heise (9.20.2008 @12:30 AM EDT)
John G. Fletcher (9.20.2008 @02:09 PM EDT)
Boris Nikolaus (09.22.2008 @05:02 PM EDT)
Kali Gajula and Ramteke Mithil (09.24.2008 @05:36 AM EDT)
Ranjit Eswaran (09.24.2008 @05:44 AM EDT)
David Gower (09.24.2008 @09:45 AM EDT)
Tinglekar Srinath (09.24.2008 @12:36 PM EDT)
Robert Sarvis (9.25.2008 @01:47 PM EDT)
Gurunandan Pai (9.26.2008 @06:41 AM EDT)
Thomas Rohr (9.26.2008 @07:42 AM EDT)
Andrea Andenna (9.28.2008 @04:17 AM EDT)
Jampani Kv Raju (9.30.2008 @03:03 AM EDT)
Alexandru Nicau (9.30.2008 @07:49 AM EDT)
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