Three Switches Solution

Label each switch 1, 2, 3. First turn on the first switch and leave it on for a few minutes. Then turn off the first switch and turn on the second switch. Now open the door. If the light is on the second switch controls the light. If it is off, touch the bulb, if the bulb is hot it’s the first switch because the light was on for a few minutes to heat up the bulb. If the bulb is cold it’s the third switch, because the bulb was never turned on.

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