quote:
Originally posted by SixOfSpades:
Here's another one:
A spy is captured by the enemy, and dragged to their prison camp. The enemy commandant doesn't want to interrogate the spy right now, as he's just about to go to bed. To ensure that the spy will stay up all night worrying (and be easier to interrogate the next morning), he tells the spy:
"I'm going to play a game with you. We're going to put you in a room with a door that has no lock. There's a guard in the hall, though, so you can't get out. The only things of interest in the room are 4 light switches--each switch controls 1 light bulb in the room across the hall. Now, if you can figure out which switch controls which bulb by daybreak, we'll let you go and give you a full hour before we come after you. The catch is that as SOON as you enter the room with the light bulbs, or even to peek inside, you will have to give your answer, then and there."
"Pleasant dreams."
What's a spy to do?
Since it's night, he can see if there's a light burning in the other room by looking at the floor near the door [img]tongue.gif[/img]
This reminds me of a similar one. Let's use the same situation where there are four switches, but only a single lamp. Naturally, only one of the switches is connected to the light bulb.
This time, as soon as the spy exits the room with the lamp, he has to say which of the four switches is the right one.
He has no tools and he cannot see the other room, nor if there's a light burning there until he enteres the room with the lamp. So he's got one single shot, and four switches to choose from. How will he do this?
(It's pretty obvious once you figure it out
)