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Three cards in a hat

Discussion in 'Politics' started by aphexcoil, Dec 29, 2002.

1. rs7

I still agree. This was your original answer and my original resonse was posted as below. I believe it ALL is exactly as you explained, and I agreed. It is about the probabilities AFTER an action has occured, which changes the entire "problem".

#31     Jan 3, 2003
2. Mr Subliminal

I don't see the difference between the above and the original problem. Unless "one side of that card is red" means only one side is red, in which case the probability of it being the card with two red sides is zero.

#32     Jan 3, 2003
3. igsi

The difference is that in the original problem the side of the card is chosen randomly while in my problem the card is chosen randomly. That changes problem's sample space.

#33     Jan 3, 2003
4. Mr Subliminal

OK, you draw your card randomly.

(1) Then what do you do?

(2) How do you formulate (1) into a probability question?

#34     Jan 3, 2003
5. igsi

(1) The subject asks if one of the sides is red and receives "yes".
(2) The same is in original problem:
"What is the probability that that card is the card with two red sides?"

#35     Jan 3, 2003
6. aphexcoil

Well, you could just do this:

A guy walks into a room with a card laying on the floor. The card looks red to the person, but the other side cannot be seen. The person is told that before he walked into the room, three cards were put into a machine in the ceiling. A random card was dropped from the machine and landed on the floor. The three cards that were originally in the machine were a red/red, red/white and a white/white card.

The person is than asked, "What is the probability that the card on the floor is the red/red card."

That would be 2/3'rds, or 66.666 (ad infinitum) percent.

#36     Jan 3, 2003
7. Mr Subliminal

In that case, we are finally in agreement

#37     Jan 3, 2003
8. igsi

So, What's new? Assuming the person is told the truth, that's the same as you posted starting this thread.

#38     Jan 3, 2003
9. aphexcoil

Right. So the solution is something we all agree on.

#39     Jan 3, 2003
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