Thursday, June 24, 2010

A coin flipping game...

I'm attending a math teacher circle workshop this week.  Yesterday afternoon we had a great speaker who talked about an old favorite of mine.

You and a friend play a game where each of you pick a sequence of three heads or tails.  Let's say your friend chooses THH and you choose HHH.  You then repeatedly flip a coin until one of the sequences shows up.  So if you flipped THTHH, your friend would win.  Is this a fair game?

Oh, if you have a solution feel free to write a comment, but give people a spoiler alert.

3 comments:

  1. This was in the Chances Are book by the Kaplan's I think right? I'm jealous you're at the math circle. Keep blogging it so I can live vicariously through you.

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  2. Knowing that this is called "Penney's game" will enable anyone who wants to to spoiler themselves :-) It's apparently discussed in Martin Gardner's "Time travel and other mathematical bewilderments" too.

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  3. Thanks! I've read lots of Gardner, but not that one and did not know this was called "Penney's game." And Jason, I've read Out of the Labyrinth, but not "Chances Are."

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