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Classic counterfeit coin problem (Posted on 2005-06-04) Difficulty: 3 of 5
In the famous "The Odd Coin" problem you are given twelve coins, exactly one of which is lighter or heavier than the other coins. You are to determine the counterfeit coin, and whether it is lighter or heavier than the other coins, in just three weighings with a balance.

Can you solve this problem with the additional restriction that you must decide what coins go on each pan for all three weighings before any weighing takes place?

See The Solution Submitted by McWorter    
Rating: 3.7500 (4 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: No Subject | Comment 3 of 13 |
(In reply to No Subject by jasper)

But, since you don't know whether the coin is heavy or light, you don't know which group to weight in your last weighing.


1: 1,2,3 = 4,5,6
2: 7,8,9 > 10,11,112
3: ??

  Posted by Sam on 2005-06-04 16:29:40

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