Brain Teasers
The Old Switch-A-Roo
Stan is applying for a job with a high paying electrician known to hire people who can think outside of the box. He tells Stan that if he can solve a particular problem, he will get the job. The boss puts Stan outside the door to a room from which light cannot escape. Inside the room is a lamp. On the wall next to Stan are four switches, one of which works the lamp, the other three do nothing. Stan needs to figure out which switch works the lamp, but the boss has taken away all of his tools. He has told Stan that he may flip the switches to his heart's content, but he can only open the door to examine the lamp once. What should Stan do with the switches to ensure he gets the job?
Hint
Light bulbs BURN brightlyAnswer
Stan flips switch "1" on for one minute then turns it off. He then flips switch "2" on for a few seconds then turns it off. Then he flips switch "4" on and opens the door. If the lamp is off and the bulb is hot, then he knows it was switch "1". If it's off and the bulb is warm then he knows it was switch "2". If it's off and cold, then it was switch "3". And obviously if it's on then it's switch "4".Hide Hint Show Hint Hide Answer Show Answer
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