Light in the Closet


Light in the ClosetSo, we are going on publishing riddles and brain games. Try to solve this one. There are three switches, one of them switches on and off the light in the closet. If you are near the switches, you cannot define, if the light is on or off in the closet. The task is to define, which of these three devices switches on the light in the closet. All switches are initially in the “on” position. At the same time you can approach the switches only once and after it go to the closet and give the answer. Please, if you want to find the solution yourself, do not look at the comments of this post, because someone could have already written it there. Good luck!

You will find the solution in the next brain game. You are always welcome to ask questions about the task, in case something is not clear. But sorry, I will not answer leading questions.

The answer to the previous brain game is: look at the busy two-way street at night, those two rivers are the flows of the cars approaching you (the white river) and moving away from you (the red one). Thank you all, guys, for your variants, you are really creative. Congratulations to Chris, who was the first one with the right answer, Nuno, Arachnivore, Nathan, Arun, Frédéric Dénommé, Jack, Willard, George! Keep it up!

Beautiful Atlanta


  1. Geniusbeauty. If you would care to e-mail me at my e-mail address I have the answer, but I do not want to spoil the game for the rest of the players.

  2. By turning off 2 switches before you go to the closet you would be able to determine the right switch with one more trip (unless you got lucky first time).

  3. Turn one switch off, wait about 10 minutes, then turn another switch off. Then quickly enter the closet.
    Using your mental powers, the answer will be obvious.

  4. Jed is absolutely correct assuming two things. 1. That the lightbulb is of the incandescent type and 2. I’ll let you figure that out.

  5. Jed, imagine, that the switches are in the other side wing of the building.
    G Templeton, you can approach the switches only ONCE and after it go to the closet and give the answer.

  6. This is quite an old brain teaser.

    Turn first switch off.
    Wait a few minutes.
    Turn second switch off.

    Enter closet.

    Bulb on = third switch
    Bulb off and hot = second switch
    Bulb off and cold = first switch

  7. So, to clarify then.
    I’m assuming that the light starts “on” since the light switch is in the “on” position. Or is that an unknown? Could THE switch be “on” but the light be “off”?

    And, presumably, the addition of the distance from one wing of the building to the other means I can’t determine the answer through touching the bulb?

  8. Jed, no, this cannot be, if the switch is in the “on” position, then the light is on. Answering the second question: let us say, it takes you about 20 seconds to get from one wing of the building to the other.

  9. I turn off the first sw. I wait 5 minutes. Then I turn off the second sw. I go immediately to the closet and I see. If it is still on is the 3 sw. If it is off, I touch the light. If it is still hot is the 2 sw, and I it is cold is the 1 sw.


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