[Guest]

This is my first post so I hope I did this right.

You are on the middle level of a house. There is a lamp upstairs that you need to turn on.

The switch for the lamp is on your level, but it is on a panel of switches with two others.

Using only one trip upstairs, how can you tell which switch turns on the upstairs lamp?

Keep in mind that there is no specific answer such as, "the middle switch", "the switch on the left", or, "the switch on the right"

The answer is merely the method to find out which switch it is.

First, turn on the switch on the left. Wait about 10 minutes. Then flip down the left switch and flip up the middle switch. Then go upstairs. If the light is on then you know that the switch in the middle was the right switch. If it is off, feel the bulb. If the bulb is hot, that means it was the switch on the left. If it is cold, then you know that it is the switch that you did not flip up, the switch on the right.

[Guest]

Done before, i think.

[rookie1ja]

Welcome to the Den, Tmaxman96. Let me direct your attention to rules of this forum (see "Important: READ BEFORE POSTING" above). Especially, the part about doing a quick search before you post old puzzles like this one - it is already part of this site. Actually, it is one of my favorites and the very first of logic puzzles. It also has many variations already posted.

And giving away the answer after a few guys give the riddle a shot is better as well.

Thread locked.