Continuing our trend of presenting great brain puzzles, here is a switchboard puzzle, a older puzzle but still a golden one.
There was an electrician who was presented with a task of identifying the correct switch for an electric bulb. There were three switches on the ground floor of a building and one bulb on the first floor. It will not be possible to see the bulb from the ground floor, neither it would be possible to see the wiring to identify the connection. The electrician can go from the ground floor to the first floor only once. After reaching the first floor, he must be able to tell the correct switch for the bulb.
Question:- What is the methodology to find out the correct switch for the bulb?
he has to switch on one switch ,after 10 secs switch off that. now on another switch. and go upstairs. now we can find out the answer easily. how means if we notice that bulb is heated & off mode our first switch is answer. otherwise if bulb is in on mode, our 2nd switch is answer. else bulb is not heated & off mode then 3rd switch is answer
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