12 Coin Hint
12 Coin Hint
Here's a helpful hint to the
12 coin problem:
If I balance 3 coins on both sides, say 1-3 against 4-6, and I find that the
balance tips one way, then I remove one from each side, say 1 and 4, then I
swap two, say 2 and 5, then if the balance tips the same way, I know it's 3 or
6; if the balance tips the other way, I know it's 2 or 5; and if the balance
is equal, then I know it 1 or 4. I also know what way the scale tipped the
first time, so isolating it down to two, I only have to measure one of the
remaining two against a known good coin to determine if it's that coin or
the other, and if it's even on that last measurement, the first measurement
tells me the orientation of the other coin.
Give up already? Here's the solution.
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