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Can someone help me please? This is

  1. Mar 7, 2005 #1
    Can someone help me please? This is urgent

    I can seem to figure this question out. I'm always left with 4 coins and 1 try.

    Using a simple balance, could you (by weighing) find the one fake (lighter) coin in a group of 27 coins. Here's the catch...you may only weigh the coins 3 times. You may not use anything else. How could this be accomplished?

    If you can get the answer as fast as possible that would help. Thanks.
  2. jcsd
  3. Mar 7, 2005 #2
    I know that someone has already done this but i cant seem to find the answer.
  4. Mar 8, 2005 #3
    1) First make three groups of nine coins. balace two of them.
    2) Again make three groups of three.Balance two of them.
    3) Now there only three coins left to check out and that's easy. :biggrin:
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