I have one to post, but want to first make sure that I can solve it myself
Sorry for the delay, I didn't want to publish a puzzle that I couldn't solve myself. When I first found this brain teaser, I thought it would just take me a wee while to figure out the logic behind it and then publish.
A few days later and even after drawing on/off switches in Excel I still hadn't found a working solution. I was stumped and had to peek at the answer.
I then groaned as I'd been looking at things from the wrong angle and not thinking outside of the box.
Having not been able to find the solution myself I was a bit hesitant about publishing it. But OTOH someone may wonder what was the puzzle that stumped me. In the end I have decided to post it, but giving you the massive clue that I didn't have - don't spend too long looking for a logic pattern in the switches.
There is a lightbulb inside a closet. The door is closed, and you cannot see if the light is on or off through the door.
However, you know the light is off to start. Outside of the closet, there are three light switches. One of the switches controls the lightbulb in the closet. You can flip the switches however you want, but once you open the door, you can no longer touch the switches.
How do you figure out without a doubt which switch controls the light?