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Brain Teaser - Scratch!

  1. Oct 9, 2007 #1
    A friend of mine is really pulling my chain. He said the answer to this was right in front of me. I doubt that! Does anyone have an idea on this?

    "I have a bar of chocolate 6 blocks wide by 9 blocks long and I want to split it into its individual blocks making the smallest number of breaks that I can. The breaks that I am allowed to make start on one side and finish on a different side without visiting a third side.

    How many breaks must I make?

    Can you generalize your answer bard that are to w blocks wide and m blocks long?"
  2. jcsd
  3. Oct 9, 2007 #2


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    Let's see. The obvious answer is 13, or w+m-2. I'm sure there's a shorter answer. That's the upper limit.
  4. Oct 9, 2007 #3
    Thank You!

    Makes sense now that I look at it! Would you elaborate w+m-2?
  5. Oct 9, 2007 #4


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    To break something into 6 pieces, you to need to make 5 breaks.

    So, specifically: 9-1 + 6-1, or generally: w-1 + m-1.
  6. Oct 9, 2007 #5
    YES!!! Thanks so much! I appreciate it!!
  7. Oct 13, 2007 #6
    Hmm, what about breaking it then stacking it and breaking it again? How thick is this bar?
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