Problem of the Week 1244
Going for Gold
Charlie has 64 identical-looking gold-colored coins; all are counterfeit except one.
He calls Alice into his office and seats her at a table containing an
Bob enters and is seated in the same position, facing the board. He may take one of the coins.
Find a joint strategy that allows Bob to select the gold coin.
As usual, Alice and Bob know the protocol in advance and can plan a strategy, but cannot communicate after Alice enters the room.
Extension: The problem above shows that
How large is C(2)? That is, still with the
Source: Heard from Paul Cuff, though this is probably an old folklore problem.
Source: Dan Velleman (Amherst College)