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Ponder This

November 2000

<<October November December>>


Ponder This Challenge:

We gave you a difficult puzzle last month.
This month's will be easier.

Part A:
Select 75 integers between 1 and 230 (inclusive) such that no
two of them differ by exactly 5, 6, or 11.

Part B:
Show that one cannot select 76 integers satisfying the same requirements.


We will post the names of those who submit a correct, original solution! If you don't want your name posted then please include such a statement in your submission!

We invite visitors to our website to submit an elegant solution. Send your submission to the ponder@il.ibm.com.

If you have any problems you think we might enjoy, please send them in. All replies should be sent to: ponder@il.ibm.com

  

Challenge: 11/03/00 @ 12:00 PM EDT
Solution: 11/30/00 @ 5:15 PM EDT
List Updated: 11/30/00 @ 5:15 PM EDT

People who answered correctly:

David McKee (11.03.2000 @ 1:03 PM EDT)
Kevin Bealer (11.03.2000 @ 1:39 PM EDT)
Ming Song (11.03.2000 @ 1:56 PM EDT)
Sujith Vijay (11.03.2000 @ 2:15 PM EDT)
Daniel Li (11.03.2000 @ 2:20 PM EDT)
Tim Edmonds (11.03.2000 @ 3:15 PM EDT)
Ashish Kadakia (11.03.2000 @ 3:59 PM EDT)
Akash Jain (11.03.2000 @ 4:51 PM EDT)
Ravishankar Arunachalam (11.03.2000 @ 6:55 PM EDT)
Jack Kennedy (11.03.2000 @ 8:53 PM EDT)
Ether Jones (11.03.2000 @ 11:01 PM EDT)
Abd Al-Rahman Said Hammad (11.03.2000 @ 11:22 PM EDT)
Jonathan Hayward (11.04.2000 @ 11:21 AM EDT)
Murali Prakash (11.04.2000 @ 12:45 AM EDT)
Joseph DeVincentis (11.04.2000 @ 11:30 PM EDT)
Achava Nakhash (11.04.2000 @ 11:51 PM EDT)
Derek Kisman (11.05.2000 @ 2:47 AM EDT)
Philip Nanni (11.05.2000 @ 2:49 AM EDT)
Anand (11.05.2000 @ 3:54 AM EDT)
Ilan Algor (11.05.2000 @ 8:29 AM EDT)
Francis Golding (11.05.2000 @ 8:43 AM EDT)
Olivier Miakinen (11.05.2000 @ 9:55 AM EDT)
Christie Bolton (11.05.2000 @ 6:31 PM EDT)
Prithu (11.05.2000 @ 7:02 PM EDT)
Brian Murphy (11.05.2000 @ 10:45 PM EDT)
Philip Dawson (11.06.2000 @ 6:27 AM EDT)
Vladimir Sedach (11.06.2000 @ 12:55 PM EDT)
Samantha Levin (11.06.2000 @ 12:37 PM EDT)
Trevor Strohman (11.06.2000 @ 2:38 PM EDT)
Alexey Vorobyov (11.06.2000 @ 2:45 PM EDT)
Craig Arnold (11.06.2000 @ 4:47 PM EDT)
Howard Smith (11.06.2000 @ 5:25 PM EDT)
John Hamilton (11.06.2000 @ 6:04 PM EDT)
Imtiaz Hossain (11.07.2000 @ 12:27 AM EDT)
Zhang Lei (11.07.2000 @ 2:19 AM EDT)
Kivanc Cefle (11.07.2000 @ 2:34 AM EDT)
Raul Saavedra (11.07.2000 @ 3:21 AM EDT)
Ed Lee (11.07.2000 @ 5:29 AM EDT)
Ashutosh Misra (11.07.2000 @ 7:26 AM EDT)
Alexis Megas (11.07.2000 @ 8:18 AM EDT)
Dave Biggar (11.07.2000 @ 10:33 AM EDT)
Guenter Mair (11.07.2000 @ 1:23 PM EDT)
Shmuel Spiegel (11.08.2000 @ 11:18 AM EDT)
Ralf Seliger (11.08.2000 @ 2:46 PM EDT)
Prashanth H Hande (11.08.2000 @ 3:37 PM EDT)
Ivan Skytte Jørgensen (11.08.2000 @ 6:28 PM EDT)
Yiu Ming (11.09.2000 @ 6:49 AM EDT)
Menka Verma (11.09.2000 @ 12:21 PM EDT)
Suman Datta (11.10.2000 @ 4:49 AM EDT)
yengyong (11.10.2000 @ 5:31 AM EDT)
Phil Strenski (11.10.2000 @ 9:06 AM EDT)
Ivan Corwin (11.10.2000 @ 1:03 PM EDT)
Viral Patel (11.10.2000 @ 4:24 PM EDT)
Imrankhan Pathan (11.11.2000 @ 11:46 AM EDT)
Amos Guler (11.12.2000 @ 8:54 AM EDT)
Samir Pawanekar (11.12.2000 @ 9:51 AM EDT)
Sverre Sand (11.12.2000 @ 7:48 PM EDT)
Michael Malak (11.13.2000 @ 11:32 AM EDT)
Catherine Bradshaw (11.13.2000 @ 11:42 AM EDT)
Kevin Vanderwater (11.13.2000 @ 9:16 PM EDT)
zakharin (11.13.2000 @ 9:47 PM EDT)
Scott Ransom (11.14.2000 @ 12:10 AM EDT)
Morten Ofstad (11.14.2000 @ 6:02 AM EDT)
Jay Cherski (11.14.2000 @ 1:05 PM EDT)
Aniket Khera (11.15.2000 @ 4:14 PM EDT)
Islam Gohar (11.16.2000 @ 8:35 AM EDT)
Tom Blumer (11.16.2000 @ 2:29 AM EDT)
Rajiv Shukla (11.17.2000 @ 10:10 AM EDT)
Cristian Stagarescu (11.17.2000 @ 8:48 AM EDT)
Michael Moyer (11.18.2000 @ 11:48 PM EDT)
Tom Kauffman (11.19.2000 @ 8:00 PM EDT)
María Elena Martínez (11.20.2000 @ 1:16 PM EDT)
Laura Apostoloiu (11.20.2000 @ 12:53 PM EDT)
A Braunsdorf (11.21.2000 @ 3:02 PM EDT)
Sudipta Das (11.23.2000 @ 6:32 AM EDT)
Maneesh Kumar Ponnath (11.23.2000 @ 6:40 AM EDT)
Johannes Schindelin (11.24.2000 @ 3:05 AM EDT)
Ludwig Deruyck (11.24.2000 @ 1:06 PM EDT)
Frank Jones (11.24.2000 @ 11:18 PM EDT)
Rocke Verser (11.27.2000 @ 9:22 AM EDT)
Henry Bottomley (11.27.2000 @ 2:05 PM EDT)
Mihai Cioc (11.28.2000 @ 1:47 PM EDT)
Ruth Christie (11.28.2000 @ 2:10 PM EDT)
Anantha Ramamurti (11.28.2000 @ 2:35 PM EDT)
Siddharth Rai (11.30.2000 @ 1:54 AM EDT)
Stephane Higueret (11.30.2000 @ 4:20 AM EDT)
Easwaran Raman (11.30.2000 @ 7:10 AM EDT)
Nagendra Gd (11.30.2000 @ 1:43 PM EDT)

red listings indicate a correct solution to part B
Timestamps reflect approximate part B time-of-receipt (where appropriate).


Attention: If your name is posted here and you wish it removed please send email to the ponder@il.ibm.com.