Puzzle #31: Three hats
23 November 2019
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From New Scientist #3257, 23rd November 2019 [link] [link]
Ariana, Beverley and Cassie are standing in a line. They know that two of them are wearing black hats and one is wearing a white hat — or vice versa — in an arrangement like the one shown above.
Beverley and Cassie can see the hats in front of them but not behind, while Ariana can’t see any hats. They can only say “white” or “black” to announce their own hat colour.
Who will be able to confidently state their hat’s colour first? And who will be second?