IBM Research | Ponder This | October 2016 challenges

# Ponder This

## October 2016

<<September October November>>

Ponder This Challenge:

Three printers print the following: the first prints the digits of e (2.71828182845904523536...), the second prints the digits of pi (3.14159265358979323846...), and the third the digits of the square root of two (1.4142135623730...). Every second, exactly one and only one of these printers prints its next digit. You have a five-digit number, and when all three printers show your number as the most recently printed five digits - you win.

Assuming you can control the order in which the three printers print their digits, what five-digit number should you choose to win as fast as possible?

For example, if we play this game for two-digit numbers, you can win after 47 seconds by selecting 23 as your number: let the first printer work for 18 seconds, then the second one for 18 seconds, and then the third for 11 seconds and we get "23" on all three. This is not the best solution, by the way - there is an even faster one.

Provide your answer as the five-digit number you selected and the length of time it took you to win in hh:mm:ss format.

Message to the solvers: Due to a technical limitation, solvers for October's challenge will only be published at the end of the month.

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: 28/09/2016 @ 12:00 PM EST
Solution: 02/11/2016 @ 12:00 PM EST
List Updated: 01/11/2016 @ 12:00 PM EST

Oleg Vlasii (28/09/2016 01:31 PM IDT)
Robert Gerbicz (28/09/2016 02:09 PM IDT)
Lorenz Reichel (28/09/2016 02:53 PM IDT)
Alex Fleischer (28/09/2016 04:24 PM IDT)
Daniel Chong Jyh Tar (28/09/2016 05:31 PM IDT)
Mark Stuckel (28/09/2016 06:54 PM IDT)
Todd Will (28/09/2016 07:10 PM IDT)
Benjamin Lui (28/09/2016 07:23 PM IDT)
Francis Golding (28/09/2016 07:32 PM IDT)
Paolo Farinelli (28/09/2016 07:39 PM IDT)
Arthur Vause (28/09/2016 07:49 PM IDT)
Bert Dobbelaere (28/09/2016 08:19 PM IDT)
Evert van Dijken (28/09/2016 10:39 PM IDT)
Harold Gutch (28/09/2016 11:11 PM IDT)
Timothy S. Lewis (28/09/2016 11:23 PM IDT)
Shouky Dan & Tamir Ganor (28/09/2016 11:43 PM IDT)
Mathias Schenker (29/09/2016 12:15 AM IDT)
Yan-Wu He (29/09/2016 05:36 AM IDT)
Teake Nutma (29/09/2016 10:40 AM IDT)
Alessandro Marzo (29/09/2016 11:46 AM IDT)
Emir Haleva (29/09/2016 11:51 AM IDT)
Luiz Friedrich (29/09/2016 11:57 AM IDT)
Florian Fischer (29/09/2016 03:13 PM IDT)
Dieter Beckerle (29/09/2016 03:28 PM IDT)
Stefano Leucci (29/09/2016 04:23 PM IDT)
Emilio Del Tessandoro (29/09/2016 06:01 PM IDT)
Edward Bentley (29/09/2016 06:07 PM IDT)
Sri Mallikarjun J (29/09/2016 06:12 PM IDT)
Kang Jin Cho (29/09/2016 06:40 PM IDT)
Serge Thill (29/09/2016 07:10 PM IDT)
Andrés Trapanotto (29/09/2016 09:27 PM IDT)
Muralidhar Seshadri (29/09/2016 09:41 PM IDT)
Alan Murray (29/09/2016 11:16 PM IDT)
Armin Krauss (29/09/2016 11:21 PM IDT)
Thomas Satzger (30/09/2016 12:06 AM IDT)
Hugo Pfoertner (30/09/2016 12:16 AM IDT)
David F H Dunkley (30/09/2016 02:13 AM IDT)
Larry Kearney (30/09/2016 03:28 AM IDT)
Jesse Rearick (30/09/2016 04:18 AM IDT)
Joaquim Neves Carrapa (30/09/2016 04:24 AM IDT)
Tyler Mullen (30/09/2016 06:12 AM IDT)
Victor Chang (30/09/2016 06:27 AM IDT)
Honglei Zhang (30/09/2016 10:18 AM IDT)
Slavisa Pajkanovic (30/09/2016 03:45 PM IDT)
Daniel Bitin (30/09/2016 05:32 PM IDT)
Joseph DeVincentis (30/09/2016 05:32 PM IDT)
Wilder Boyden (30/09/2016 07:00 PM IDT)
Hamidreza Bidar (30/09/2016 07:05 PM IDT)
Leandro Araújo (30/09/2016 10:07 PM IDT)
Clive Tong (30/09/2016 11:33 PM IDT)
Reiner Martin (01/10/2016 01:23 AM IDT)
Nigel Brumpton (01/10/2016 11:11 AM IDT)
Raymond Lo (01/10/2016 01:26 PM IDT)
Michael Liepelt (01/10/2016 06:40 PM IDT)
Dezhi Zhao (01/10/2016 08:32 PM IDT)
Marcelo De Barros (01/10/2016 08:47 PM IDT)
Motty Porat (01/10/2016 11:47 PM IDT)
Amos Guler (02/10/2016 02:25 AM IDT)
Vijay Ganti (02/10/2016 03:40 AM IDT)
Eric Koh (02/10/2016 11:36 AM IDT)
Shirish Chinchalkar (02/10/2016 02:54 PM IDT)
Scott Walters (02/10/2016 04:35 PM IDT)
Bryce Fore (02/10/2016 08:00 PM IDT)
Bryan Brady (03/10/2016 02:29 AM IDT)
Serge Batalov (03/10/2016 02:35 AM IDT)
Gary M. Gerken (03/10/2016 06:19 AM IDT)
Lavanya Kannan (03/10/2016 06:11 PM IDT)
KK Ng (03/10/2016 06:51 PM IDT)
Harald Bögeholz (03/10/2016 09:44 PM IDT)
Christian Pfaffenzeller (03/10/2016 10:24 PM IDT)
Shwetabh Garg (03/10/2016 10:45 PM IDT)
Andreas Stiller (04/10/2016 12:27 AM IDT)
Liubing Yu (04/10/2016 01:25 AM IDT)
Leo Broukhis (04/10/2016 01:55 AM IDT)
Bradley Sherman (04/10/2016 02:27 AM IDT)
Tom Miller (04/10/2016 05:58 AM IDT)
Thomas Egense (04/10/2016 03:05 PM IDT)
Joel Christophel (04/10/2016 04:12 PM IDT)
Itay Hazan (04/10/2016 07:29 PM IDT)
Kevin Petrychyn (04/10/2016 08:30 PM IDT)
Jimmy Waters (04/10/2016 10:01 PM IDT)
Brandon Chupp (05/10/2016 01:27 AM IDT)
Mark Murphy (05/10/2016 04:53 AM IDT)
Joe Riel (05/10/2016 07:19 AM IDT)
Jordan Leaman (05/10/2016 05:07 PM IDT)
Brad Blackard (06/10/2016 12:03 AM IDT)
Adir HaCohen (06/10/2016 02:25 AM IDT)
Lee Gao (06/10/2016 03:24 AM IDT)
Franciraldo Cavalcante (06/10/2016 05:23 AM IDT)
Lawrence Hon (06/10/2016 07:34 AM IDT)
Goh Koon Hui Geoffrey (06/10/2016 09:07 AM IDT)
Erik Hostens (06/10/2016 04:18 PM IDT)
David Greer (06/10/2016 05:48 PM IDT)
Chris Lau (06/10/2016 11:14 PM IDT)
Nagendra Gulur (07/10/2016 06:36 AM IDT)
Vikram Gupta (07/10/2016 03:17 PM IDT)
Peter Gerritson (07/10/2016 10:02 PM IDT)
Jacob Levinson (08/10/2016 12:34 AM IDT)
Greg Janée (08/10/2016 08:59 AM IDT)
Tim Cieplowski (08/10/2016 10:09 PM IDT)
Nis Jørgensen (09/10/2016 11:43 PM IDT)
Austin Huff (10/10/2016 01:59 AM IDT)
Rogerio Ponce da Silva (10/10/2016 03:30 AM IDT)
Aharon Malachi (10/10/2016 01:39 PM IDT)
Andreas Puccio (10/10/2016 03:20 PM IDT)
Sandro Feuz (10/10/2016 04:32 PM IDT)
Hao Zheng (10/10/2016 06:07 PM IDT)
Connor Stoyle (10/10/2016 09:01 PM IDT)
Fabian Valka (12/10/2016 01:32 AM IDT)
Anoop Ghanwani (12/10/2016 08:45 AM IDT)
Fabio Filatrella (12/10/2016 04:15 PM IDT)
Oleg Bogatchev (12/10/2016 10:46 PM IDT)
Joël Bleuse (13/10/2016 10:06 AM IDT)
Aviv Nisgav (13/10/2016 01:19 PM IDT)
Alex Zdanowicz (14/10/2016 12:36 AM IDT)
Francisco Couzo (15/10/2016 06:18 AM IDT)
Ralf Bonse (16/10/2016 09:58 PM IDT)
Greetings Dominik Lenz (17/10/2016 01:00 AM IDT)
Andreas Eisele (17/10/2016 10:47 AM IDT)
Alain Stephan (17/10/2016 10:55 AM IDT)
Grzegorz Gawlik (17/10/2016 10:57 PM IDT)
Deema Alamer (18/10/2016 11:11 AM IDT)
Spiros Antonatos (18/10/2016 04:00 PM IDT)
Martin Sergio H. Faester (18/10/2016 05:14 PM IDT)
Tilmann Steinberg (19/10/2016 02:17 AM IDT)
Michael Chirozzi (19/10/2016 11:52 PM IDT)
Pawel Romanko (20/10/2016 11:44 PM IDT)
John Spurgeon (22/10/2016 01:59 AM IDT)
Martin Thiim (23/10/2016 12:58 PM IDT)
Samantha Casanova (24/10/2016 10:19 PM IDT)
Anders Bisbjerg Madsen (25/10/2016 10:16 PM IDT)
Robert Lang (26/10/2016 04:13 PM IDT)
Erik Wünstel (26/10/2016 10:36 PM IDT)
Frank Schoeps (26/10/2016 10:37 PM IDT)
Alok Menghrajani (27/10/2016 12:52 AM IDT)
Ran Sharon (27/10/2016 02:21 PM IDT)
Guenter Nowak (28/10/2016 04:15 AM IDT)
Shmuel Menachem Spiegel (28/10/2016 06:07 AM IDT)
Stephen Dalton (28/10/2016 10:05 PM IDT)
Siddharth Joshi (29/10/2016 03:21 PM IDT)
Christian Pape (29/10/2016 03:48 PM IDT)
Boris Rakus (30/10/2016 11:55 AM IDT)
Albert Stadler (30/10/2016 03:47 PM IDT)
Walter Schmidt (30/10/2016 07:18 PM IDT)
Sergey E. Koposov (30/10/2016 10:39 PM IDT)
Stephanie Li (30/10/2016 11:31 PM IDT)
Joehyun Kim (31/10/2016 01:06 AM IDT)
Jang Hun Choi (31/10/2016 01:45 AM IDT)
Joo Sung Yi (31/10/2016 04:29 AM IDT)
Mauro Bampo (31/10/2016 09:32 AM IDT)
José Eduardo Gaboardi de Carvalho (31/10/2016 08:55 PM IDT)
Yevgeniy Parfilko (31/10/2016 09:37 PM IDT)
Radu-Alexandru Todor (01/11/2016 01:37 AM IDT)