27 Coins Balance Puzzle

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Twenty-six coins weigh the same and one counterfeit coin weighs less than the others. Determine the counterfeit coin using a balancing scale with the least number of tests. Do you think you can find the counterfeit coin with only three tests?


The numbers at the bottom are neither on the left nor the right for the current weighing. Only the largest number of the coins on either side is shown in the weighing pans.


Contributed by: Min Ho Bae (February 2015)
Open content licensed under CC BY-NC-SA




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