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!
Tbh, I quite enjoy the question / challenge. But on the other hand I've been a dev for awhile so could also easily give a long list of real world examples of clients asking me ridiculous (and sometimes interesting) questions.