Solution to Puzzle 38

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The puzzle was 

There is a closet and a light bulb inside this closet. You can not see whether the bulb is on or off from outside. There are three switches outside the closet one of which controls the light bulb. You can not see these switches from the closet. How do you find out which switch controls the bulb with a single try?

Now let us look at the solution.

  • Switch on the first switch wait for 2-3 minutes and then switch it off.
  • Switch on the second switch.
  • Now go inside the closet. If the bulb is on, then second switch is the switch for the bulb.
  • If bulb is off, touch it. If it is warm then first switch is the switch. If not third switch is the switch for the bulb

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