Problem #22 HARD
The Marked Coin
Google Lateral Thinking Logic
Problem Statement
A coin inspector has 12 coins that look identical. Exactly one coin is counterfeit — it is either slightly heavier or slightly lighter than the 11 genuine ones, but the inspector does not know which direction. Using a balance scale with no weights, the inspector must not only identify the counterfeit coin but also determine whether it is heavier or lighter — all within exactly 3 weighings. How?
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