The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Australian Mathematical Society - Hat Puzzle
Replies: 4   Last Post: Mar 4, 2013 7:21 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Wally W.

Posts: 283
Registered: 6/15/11
Re: Australian Mathematical Society - Hat Puzzle
Posted: Mar 3, 2013 2:50 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On Sun, 3 Mar 2013 11:35:41 -0800 (PST), Pratik Poddar wrote:

>Posted on:
>Problem: The Mad Hatter is holding a hat party, where every
>guest must bring his or her own hat. At the party, whenever two guests greet each other, they have to swap their hats. In order to save time, each pair of guests is only allowed to greet each other at most once.
>After a plethora of greetings, the Mad Hatter notices that it is no longer possible to return all hats to their respective owners through more greetings. To sensibly resolve this maddening conundrum, he decides to bring in even more hat wearing guests, to allow for even more greetings and hat swappings. How many extra guests are needed to return all hats (including the extra ones) to their rightful owners?
>About the blog: CSE Blog ( ) is a collection of 225+ Quant, Math & Computer Science Puzzles for Interview Preparation & Brain Teasing with Solution. It has had more than 300,000 page views since last 3 years. I hope you will enjoy it. Cheers!

How sociable are the guests? Maybe they don't meet every other guest.

Must a guest exchange hats with the host when they meet?

May a guest exchange hats with the host? If so, how many times may the
host exchange hats with a guest? If there is no restriction on the
host's actions, no extra guests are needed.

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.