A famous ruby necklace vanished from a hotel safe. The manager swore the combination was a secret only he knew. Detective Reed examined the numeric keypad and noticed that the keys for digits 3, 4, 7, and 9 were worn down significantly more than the others. What did this tell Reed?
The combination uses those four numbers
Frequent use wears down specific keys on a mechanical or rubber keypad. The combination is restricted to a 4-digit permutation of 3, 4, 7, and 9, drastically narrowing down the suspect pool.
About this riddle
Detective riddles are tiny mysteries. Look for the detail in the story that does not fit; it is usually the clue that solves the case.
Difficulty: Medium. More like this: Detective riddles with answers or try Truth & Lie Island for a different kind of puzzle.
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