Post:

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.


Comment:

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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[–] 36 points 10 months ago (5 children)

The answer isn’t intuitive anymore now that lightbulbs don’t always get hot 🥲

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  • [–] 30 points 10 months ago* (4 children)

    It wasn't intuitive before, either, without making an absolute ton of horrible assumptions.

    • Are the wires even connected?
    • Does only one switch control the light?
    • Did the light start on or off?
    • Is the light bulb in arm's reach?
    • Can I bring my friend and just yell to each other?
    • Can I just leave the door open and see whether it turns on or not?
    • It says I'm allowed to visit the bulb room once but never actually mentions the switch room - do I start there? Can I go back after visiting the bulb room?
    • And, as you said, what type of bulb is it?

    Anyone who doesn't explore the assumptions should probably fail that particular interview question.

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  • [+] -9 points 10 months ago (3 children)

    I’ll be honest, a lot of those are pretty stupid

    Obviously the wires are connected

    Obviously one switch controls the light

    Obviously the lights start off

    In a thought experiment you can magically reach the lightbulb if you want

    Obviously you cannot bring a friend

    Obviously you cannot see the light from the switch

    Obviously you return to the switches

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  • [–] 9 points 10 months ago (2 children)

    lol

    Every time you say "obviously" to an assumption, someone else gets the job.

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