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!
Easy, take a spare phone set up a video call between that phone and your normal phone, leave the spare phone in the lightbulb room.
Go to the light switch room and start flipping switches while looking at your normal phone.
Or with one phone, set it up in a place to see the bulb and take a video. Two options:
with the video recording, scream AS LOUD AS YOU CAN the number of the switch you flip on then off. Hopefully loud enough to hear it on the video. Are you in another building? scream louder!
Start the video recording and you counting 1…2…3… and keep counting on second at a time, in time (or close enough) to the timestamp. Flip on the switches and make note of when you do (e.g. 30-35 sec, 40-45, 50-55) then go back and watch the video.
If it were me, I would do the first one.