The unbelievable solution to the 100 prisoner puzzle. @standupmaths

Uploaded November 2019 | Updated September 2026, 2 weeks ago

Yes, here is the follow-up video: youtube.com/watch?v=gusXBTyg1O4

Order Alex Bellos's book now and get a limited-edition 'Matt verified' copy.
mathsgear.co.uk/collections/books/products/signed-copy-of-so-you-think-youve-got-problems-by-alex-bellos-pre-order

Thanks to Matt Scroggs and the Chalkdust folks for helping organise the volunteers and the maths.
chalkdustmagazine.com

Cheers to the Ri for letting us film in their building.
rigb.org

We have free Think Maths work sheets for any teachers who want to use the prisoner puzzle in their lessons.
think-maths.co.uk/standupmaths-videos?yt-frog#prisoner-problem

CORRECTIONS
- Yes, it seems we can’t spell success successfully.
- Turns out we do know there is a limit.
- Let me know if you spot any other mistakes!

Thanks as always for Jane Street being my principal sponsor.
janestreet.com

Thanks to my Patreon supporters who help make these videos possible. Here is a random subset:

Everett Chouinard
Lucie
Christian Martel
Joost Smits
Rhys Llewellyn
Anthony Allan

Support my channel and I can make more maths videos:
patreon.com/standupmaths

Filming and editing by Trunkman Productions
Music by Howard Carter
Design by Simon Wright

MATT PARKER: Stand-up Mathematician
Website: standupmaths.com
Maths book: wwwh.umble-pi.com
Nerdy maths toys: mathsgear.co.uk

The unbelievable solution to the 100 prisoner puzzle.

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$Recursive PowerPoint Presentations [Gone Fractal!] Thanks to Steve Mould for filming with me. Check out his How viruses self assemble video. https://youtu.be/3X6qEE2fHvE We have since made the t-shirt Im wearing available for purchase: https://fotsn.teemill.com/collection/recursive-t-shirt/ We have some free teaching resources for anyone who wants to make a large collaborative fractal! As well as complicated 3D ones weve made a new Think Maths low-prep giant Sierpinski triangle guide. http://think-maths.co.uk/standupmaths-videos?yt-PPT-fractals#PPT-fractals The second channel video takes a closer look at the pptx file and the details of what version of PowerPoint you need to make this work. https://youtu.be/5Mltw6cTb-s Tom Wildenhain has since made far more successful PowerPoint fractals than Steve and I were anywhere near. https://youtu.be/O8l_awjgoMI If you want to see the live An Evening of Unnecessary Detail show: its once a month in London. https://festivalofthespokennerd.com/show/an-evening-of-unnecessary-detail/ Some technical details about the Cantor Set. http://mathworld.wolfram.com/CantorSet.html CORRECTIONS - Nothing yet. Let me know if you spot anything! Thanks to my Patreon supports who do support these videos and make them possible. Here is a random subset: Simon Hutchings Philippe von Bergen Richard Fourie Alan Flett James Tanner Support my channel and I can make more maths videos: https://www.patreon.com/standupmaths Filming and editing by Trunkman Productions: http://trunkman.co.uk Sound production by Peter Doggart Music by Howard Carter Design by Simon Wright MATT PARKER: Stand-up Mathematician Website: http://standupmaths.com/ Maths book: http://wwwh.umble-pi.com Nerdy maths toys: http://mathsgear.co.uk/$

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