Hint to question #11: Opening a Safe Without the Combination
11. You are to open a safe without knowing the combination. Beginning with the dial set at zero, the dial must be turned counter-clockwise to the first combination number, (then clockwise back to zero), and clockwise to the second combination number, (then counter-clockwise back to zero), and counter-clockwise again to the third and final number, where upon the door shall immediately spring open. There are 40 numbers on the dial, including the zero.
Without knowing the combination numbers, what is the maximum number of trials required to open the safe (one trial equals one attempt to dial a full three-number combination)?
This is a puzzle, a lateral thinking riddle. The answer is clearly not 40x40x40
The best help I can give you is to really think about the significance of the word 'immediately'
in the question.
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