From the Common Sense Problem Page


Opening a Safe

The combination of a safe consists of 3 numbers between 1 and 50, with a tolerance of plus/minus two. No one knows what the combination is. Infer (a) that it will not be possible to open the safe using the combination within 5 minutes (unless you are very lucky); (b) that it will be possible in a couple of days work.

Contributed by Ernie Davis (, New York University, U.S.A. (18th September 1997)

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