Inside a room (with a closed door) we have three light bulbs, marked A, B and C. Outside the room there are three on-off switches, marked 1, 2 and 3 (the switches of course have labels saying "on" and "off"). Each of the switches is connected to its own bulb.

Your job is to figure out which switch belongs to which light bulb.

You have to follow these rules:

1) Standing outside the room (with the door closed), you can flip the switches the way you wish.

2) After that, you are allowed to open the door and enter the room once.

3) After coming out of the room, you can not touch the switches anymore.

So how do you solve this one?

Inside a room (with a closed door) we have three light bulbs, marked A, B and C. Outside the room there are three on-off switches, marked 1, 2 and 3 (the switches of course have labels saying "on" and "off"). Each of the switches is connected to its own bulb.

Your job is to figure out which switch belongs to which light bulb.

You have to follow these rules:

1) Standing outside the room (with the door closed), you can flip the switches the way you wish.

2) After that, you are allowed to open the door and enter the room once.

3) After coming out of the room, you can not touch the switches anymore.

So how do you solve this one?

Turn "On" switches 1 and 2 and leave on for 5 minutes. After 5 minutes, turn "Off" switch 2 (leave 1 "On.") Enter the room: One bulb with be lit, that is connected to switch 1. One bulb will be warm to the touch, that is connected to switch 2. One bulb will be cold, that is connected to switch 3.

Being this one was posted not very long ago and I already saw the solution, I won't say anything for those that may not have seen it. But probably most have already seen it being I think it was only a month or so ago.

Being this one was posted not very long ago and I already saw the solution, I won't say anything for those that may not have seen it. But probably most have already seen it being I think it was only a month or so ago.

Sorry about that, folks. I didn't know that this riddle had been posted on TV recently (maybe I should have used the search function ).

Nevertheless, I guess you agree that this riddle is a tricky one, as it can not be solved "strictly mathematically". For me it took almost an hour to figure this puzzle out the first time I saw it.

Cheers