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!
I mean, my solutions either require more information or for the question to be stupidly open-ended.
I’m fond of “leave the door open”, but that only works if the doorway is visible from the switches and the space between too bright.
“send someone else into the room and call them” requires the freedom to do that, but end-runs the need for me to go into the room entirely.
Gimme two smartphones and I’m video-calling one I leave in the room.
In all of my answers and others I’ve seen so far, we’re either making presumptions or making shit up. The question fails as an “only one right answer with only the information given” logic test, but would work to reveal how we approach problems - a personality test.
Walk in, remove light. Now none of the switches control the light.
I saw the “break the bulb” solution before I commented one. Points for the most straight-forward solution, assuming its a simple light-source and not something more secure that a few bulbs at most.