# Can You Solve The Spies Sharing Secrets Puzzle?

Thanks! Share it with your friends!

URL

Sorry, only registred users can create playlists.

## Description

After a successful mission, each of N spies obtains a unique secret. By protocol, the spies share secrets by a series of phone calls between 2 spies at a time. During a call, a spy can share all the secrets the knows, including secrets learned from previous calls. What is the minimum number of phone calls so that all spies learn all secrets? Solve if the phone call is 1-way (only the caller can transmit information) and if the phone call is 2 way (both spies can learn each other's information).

Video with proofs of minimum number of calls: https://youtu.be/tGKX39ZmBwY

Blog post (with links to proofs and many references): http://wp.me/p6aMk-4JV

This puzzle is also known as the "gossip problem," and MathWorld has an entry on that:

http://mathworld.wolfram.com/Gossiping.html

Special Thanks To Patrons!

Kyle

Alberto Nishikawa

Brian M. Mooney

If you like my videos, you can support me at Patreon: http://www.patreon.com/mindyourdecisions

Connect on social media. I update each site when I have a new video or blog post, so you can follow me on whichever method is most convenient for you.

My Blog: http://mindyourdecisions.com/blog/

Twitter: http://twitter.com/preshtalwalkar

Facebook: https://www.facebook.com/pages/Mind-Your-Decisions/168446714965

Google+: https://plus.google.com/108336608566588374147/posts

Pinterest: https://www.pinterest.com/preshtalwalkar/

Tumblr: http://preshtalwalkar.tumblr.com/

Instagram: https://instagram.com/preshtalwalkar/

Patreon: http://www.patreon.com/mindyourdecisions

Newsletter (sent about 2 times a year): http://eepurl.com/KvS0r

My Books

"The Joy of Game Theory" shows how you can use math to out-think your competition. (rated 4/5 stars on 23 reviews) http://amzn.to/1uQvA20

"The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" is a handbook that explains the many ways we are biased about decision-making and offers techniques to make smart decisions. http://amzn.to/1o3FaAg

"Math Puzzles Volume 1" features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Volume 1 is rated 4.5/5 stars on 11 reviews. http://amzn.to/1GhUUSH

"Math Puzzles Volume 2" is a sequel book with more great problems. http://amzn.to/1NKbyCs

"Math Puzzles Volume 3" is the third in the series. http://amzn.to/1NKbGlp

"40 Paradoxes in Logic, Probability, and Game Theory" contains thought-provoking and counter-intuitive results. (rated 4.9/5 stars on 7 reviews) http://amzn.to/1LOCI4U

"The Best Mental Math Tricks" teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 3 reviews) http://amzn.to/18maAdo

"Multiply Numbers By Drawing Lines" This book is a reference guide for my video that has over 1 million views on a geometric method to multiply numbers. http://amzn.to/XRm7M4

Video with proofs of minimum number of calls: https://youtu.be/tGKX39ZmBwY

Blog post (with links to proofs and many references): http://wp.me/p6aMk-4JV

This puzzle is also known as the "gossip problem," and MathWorld has an entry on that:

http://mathworld.wolfram.com/Gossiping.html

Special Thanks To Patrons!

Kyle

Alberto Nishikawa

Brian M. Mooney

If you like my videos, you can support me at Patreon: http://www.patreon.com/mindyourdecisions

Connect on social media. I update each site when I have a new video or blog post, so you can follow me on whichever method is most convenient for you.

My Blog: http://mindyourdecisions.com/blog/

Twitter: http://twitter.com/preshtalwalkar

Facebook: https://www.facebook.com/pages/Mind-Your-Decisions/168446714965

Google+: https://plus.google.com/108336608566588374147/posts

Pinterest: https://www.pinterest.com/preshtalwalkar/

Tumblr: http://preshtalwalkar.tumblr.com/

Instagram: https://instagram.com/preshtalwalkar/

Patreon: http://www.patreon.com/mindyourdecisions

Newsletter (sent about 2 times a year): http://eepurl.com/KvS0r

My Books

"The Joy of Game Theory" shows how you can use math to out-think your competition. (rated 4/5 stars on 23 reviews) http://amzn.to/1uQvA20

"The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" is a handbook that explains the many ways we are biased about decision-making and offers techniques to make smart decisions. http://amzn.to/1o3FaAg

"Math Puzzles Volume 1" features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Volume 1 is rated 4.5/5 stars on 11 reviews. http://amzn.to/1GhUUSH

"Math Puzzles Volume 2" is a sequel book with more great problems. http://amzn.to/1NKbyCs

"Math Puzzles Volume 3" is the third in the series. http://amzn.to/1NKbGlp

"40 Paradoxes in Logic, Probability, and Game Theory" contains thought-provoking and counter-intuitive results. (rated 4.9/5 stars on 7 reviews) http://amzn.to/1LOCI4U

"The Best Mental Math Tricks" teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 3 reviews) http://amzn.to/18maAdo

"Multiply Numbers By Drawing Lines" This book is a reference guide for my video that has over 1 million views on a geometric method to multiply numbers. http://amzn.to/XRm7M4

## Post your comment

## Comments

Be the first to comment