Puzzle of the 3 light switches

In the basement there are 3 light switches in the off position.
Each switch controls 1 of 3 light bulbs on the floor above.
You may move any of the switches, but you may only go up stairs one time.
How can you determine which switch controls each light?

Replies

  • Saandeep Sreerambatla
    Saandeep Sreerambatla
    This is one of the interview question when I was a fresher.

    Answer:

    Let the switches be S1, S2, S3.

    Switch on S1 wait for 10 mins, Switch off S1 and Switch on S2.

    Go to the floor, the one which is glowing corresponds to S2, fell the other two.
    The one which is hot will be s1 and the other will be S3.
  • shreyasm89
    shreyasm89
    @ES- Nice answer. Is that the only solution?
  • Saandeep Sreerambatla
    Saandeep Sreerambatla
    shreyasm89
    @ES- Nice answer. Is that the only solution?

    I am not very sure, but this is the only one I said 😀 after getting a clue called you need to understand the principle of a bulb, it glows and .... it gets hot 😀

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