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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[–] NaibofTabr@infosec.pub 210 points 17 hours ago (5 children)

This assumes several things to be true, which might not be true:

power is available/the upstream circuit is on (always a bad assumption to make)
the bulb is an incandescent type that will generate an appreciable amount of heat in a short amount of time
the bulb was in the off state before you changed the position of any switches, and has been off long enough to be cold
the bulb is connected to any of the switches
the bulb is connected to only one of the switches (parallel circuits are a thing, as are multi-switch lighting circuits)

If any of the above is not true, the conclusion is invalid.

[–] OpenStars@piefed.social 7 points 7 hours ago

Also that the labels are as shown. For all we know the internal wiring is switched, and if that were the case then some could have Up=On while others have Up=Off but not all matching.

[–] hikaru755@lemmy.world 4 points 7 hours ago

Also:

I still remember which switch is which after having checked the bulb

[–] partial_accumen@lemmy.world 127 points 16 hours ago (2 children)

I'll go one further:

Assumes the bulb is in reach. When I read the problem I assumed the bulb was in a ceiling fixture out of reach. Nowhere in the text description did it specify the physical location, except "in the other room".

[–] TeamAssimilation@infosec.pub 34 points 14 hours ago (1 children)

The biggest flaw is that it assumes you’ll add conditions you’re not explicitly told are allowed. Many, many problems in school would be trivial if changing the terms beyond what’s stated was allowed.

[–] neatchee@piefed.social 2 points 3 hours ago

This is often exactly what the interview question is testing. Many of these questions are not about the solution but about how the applicant approaches problems

[–] db2@lemmy.world 18 points 14 hours ago

Also the image shows all 3 switches are on.

[–] taiyang@lemmy.world 9 points 11 hours ago

I love the idea of someone trying this stupid question irl only to realize it wasn't even plugged in. That's ... well fuck, that's most IT work. The convoluted approach is definitely the wrong one. Lol

[–] SmoothLiquidation@lemmy.world 35 points 15 hours ago (1 children)

If I asked this question during an interview and the candidate gave me this list of assumptions, I would recommend the candidate. This is exactly what I would be looking for by asking a vague question, not if they memorized the answer to a bunch of riddles, but how they thought and what their line of thought was for troubleshooting the answer.

[–] NaibofTabr@infosec.pub 13 points 13 hours ago* (last edited 13 hours ago)

I tend to agree with this line of thinking. If you're trying to hire an effective problem solver, well the first step to solving any problem is understanding the problem - the whole problem - and often more importantly the context in which the problem exists.

And while my first reaction is to be frustrated with the person asking for a solution to such a vague problem... in the real world problems are rarely clearly stated, and frequently misstated. Investigating the apparent conditions of the problem is always necessary, and generally the fastest path to resolution.