this post was submitted on 25 Dec 2025
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Programmer Humor

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You have three switches in one room and a single light bulb in another room. You are allowed to visit the room with the light bulb only once. How do you figure out which switch controls the bulb? Write your answer in the comments before looking at other answers.


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If this were an interview question, the correct response would be "Do you have any relevant questions for me? Because have a long list of things that more deserving of my precious time than to think about this!

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[โ€“] 18107@aussie.zone 4 points 2 days ago (1 children)

Walk in, remove light. Now none of the switches control the light.

[โ€“] MachineFab812@discuss.tchncs.de 2 points 2 days ago* (last edited 1 day ago)

I saw the "break the bulb" solution before I commented. Points for the most straight-forward solution, assuming its a simple light-source and not something more secure that a few bulbs at most.