Re: a (simple, but fun) riddle
Alternately, take 11 coins and flip them. This makes pile one, and the rest make pile 2.
If a coin you pick up was heads and you flip it, then it is tails in pile 1 and pile 2 has one less heads.
If a coin you pick up was tails and you flip it, then it is heads in pile 1 and equals one of the other heads which are in pile 2
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