Recently I watched the movie named "La habitación de Fermat". It is basically about people trapped in a shrinking room. They have to solve riddles or the room will get smaller eventually killing them.

Some of the riddles were nice, so I figured I share them with you. If you know the answer, post it and please come up with a new similar riddle.

First one:

You are in a room with no windows, 3 light switches and a closed door. Outside is a bulb and one of the switches is controlling it. You may turn the switches on and off as many times as you like. But when you open the door, you must tell exactly which of the switches is controlling the bulb. You can't go back into the room and try again. How can you do this?

You peek through the keyhole!

you play 'madina lake' on your ipod and it will reveal the working switch...

This, or let one of the others test if there's electricity on the switch with a bodypart

Nooooooo.

It is an old fashioned light bulb, you can hear it when it goes on. So you switch, then you listen by the door.

Or you wait until dark and then you can see a stripe of light coming underneath the door when you turn on the correct switch.

Correct! Next riddle, please!

Providing you can not phone McGyver, see light underneath the door, or hear through the door.

I guess you could flick one of the switches, masturbate or whatever for quite a while, 20mins or something, then turn it off. Then turn on another switch. Then run out of the room. If its on, then it was the switch you just pressed, if its not on then you'll need to cheat and inspect the bulb. It should be warm and/or you should be able to smell it if its an older bulb... if its a halogen or some energy saving bulb you might be fucked though, but it should have some heat because its a defect with the way we produce light. If its not warm (or doesn't smell), and the light isn't on its the other switch.

The heat thing should do, that's how I know if some fucker has been playing with my electronics

I just watched the movie so I'm not gonna mention anything besides that I hate riddles. It's always like 'I know that one, what was it again?!?'

Spud got it right with the heat. Please post another one, maybe from the same movie.

damn it wasnt the 'madina lake'

Ah yeah, the heat thing. Damn, I forgot.

I think it depends how you were going to St. Ives. By bus? If so you have to count the driver... Were there other passengers, or just the man you met and the cats and wives? I'm confused.

only 1.

Zero. Maybe 1 if you are a cat. Is this from Die Hard 3?

the answer is 1

the only person going according to the first line is the narrator. the last sentence is to throw you off, dont read too much into the problem

Pfft, that was way too easy.

Easy or not, we need another riddle.

Okay here is a hard nut....

You are trapped in a room with 5 foot thick steel walls, an equally thick steel ceiling, and no door. You have to escape and there are only two objects in the room: a mirror and a table. How do you escape?