PDA

View Full Version : Riddle me this


binions
01-29-2005, 02:09 PM
3 men go into a pitch black room. In that room, there are 3 white beanies, and 2 black beanies. The 3 men know this.

They each pick up a beanie in the dark, and put it on their head. They walk outside. They can't see what color beanie they have on, only what's on the other guys' heads.

The first guy says, "Based on what I see, I don't know what color beanie I have on."

The second guy says, "Based on what you said and what I see, I don't know what color beanie I have on."

The third guy is BLIND. He says "Based on what you have said, I know what color beanie I have on."

What color beanie does the blind man have on, and how does he know?

blank frank
01-29-2005, 03:40 PM
White.

The only way the first guy knows is if he sees two black beanies. Then only a white beanie could be left. So he didn't see two blacks. Therefore, if the second guy sees a black beanie on the blind guy, guy two knows he has a white beanie on. But he doesn't know, so he couldn't have seen a black beanie, so the blind guy must be wearing white.

The riddle I can't figure out is: what does this have to do with probability?

binions
01-29-2005, 04:19 PM
[ QUOTE ]
White.

The only way the first guy knows is if he sees two black beanies. Then only a white beanie could be left. So he didn't see two blacks. Therefore, if the second guy sees a black beanie on the blind guy, guy two knows he has a white beanie on. But he doesn't know, so he couldn't have seen a black beanie, so the blind guy must be wearing white.

The riddle I can't figure out is: what does this have to do with probability?

[/ QUOTE ]

Correct. Good job.

As to your question, nothing really. I was reminded of it when I read Ed's Microsoft riddle.