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Switches and Bulbs Logic

HardCoding00:00
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Your question is Switches and Bulbs Logic. Take a moment with it on the right.

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Problem

You are in a room with 3 switches which correspond to 3 bulbs in another room and you don't know which switch corresponds to which bulb. You can only enter the room with the bulbs once. You can NOT use any external equipment (power supplies, resistors, etc.). How do you find out which bulb corresponds to which switch?