Comments on: Chameleon Coins
https://blog.tanyakhovanova.com/2016/12/chameleon-coins/
Mathematics, applications of mathematics to life in general, and my life as a mathematician.Sun, 22 Jan 2017 03:54:35 +0000
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By: Felix
https://blog.tanyakhovanova.com/2016/12/chameleon-coins/#comment-12462
Sun, 22 Jan 2017 03:54:35 +0000https://blog.tanyakhovanova.com/?p=1257#comment-12462Let A, B, C, D be the four coins.
First, weigh A+B against C+D. If one side is lighter, then the side is guaranteed to have the fake coin. If not, then we know the chameleon was behaving as a fake coin, and it’s not on the same side as the fake coin.
Then, weigh A against B. We know at least one of them is real. If one side is lighter, then we have found the fake coin. Otherwise, the other has to be the chameleon, and we know the fake coin is either C or D.
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