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Can you find diffrent ball by three times?

  1. May 18, 2012 #1
    There are 12 balls, including a ball with other balls, it is lighter or heavier than others, can you use a Balance without weights to find out the different ball Up to three times?
    Last edited: May 18, 2012
  2. jcsd
  3. May 18, 2012 #2
    Unfortunately, I'm not sure if this is really for "General Math," this is a pretty well-known puzzle, and relies on one's general cleverness as opposed to one's mathematical cleverness.

    Probably a better translation would be (no offence):

    "Suppose you have three balls, one of which is either lighter or heavier than the others. With a balance-based scale, is it possible to determine which ball is the one with a different weight, and whether it's heavier or lighter, in three balances?"
  4. May 18, 2012 #3
    there are twelve balls,but one of them is different.
    Different is its weight
  5. May 18, 2012 #4
    can you find the different one ?
    Only one way
  6. May 18, 2012 #5


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    You have now posted 7 times in this one thread with only two responses. Yes, Chinese mathematics has a long and noble heritage. And determining which of a set of balls, or coins, weight more or less than the others is an old, traditional puzzle (it even appears in one of the old "Zork" computer games by Infocom). But what is your point?
    Last edited by a moderator: May 18, 2012
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