🚀 go-pugleaf

In article <C1GuHw.zuF@austin.ibm.com> bmoore@sunfish.austin.ibm.com (Bryan Moore) writes:
 > Ralph, you are dead wrong.
No, strange enough, Ralph's answer is right.
The question was: you meet one girl, what are the chances of the other also
being a girl.  This question has a different solution than when one of the
parents tells you that there is one girl.

 >                                            We're saying that both children
 > have been born and you see one of them on the street, you don't know which
 > child). You see a girl, what's the probability the other is a girl. 
Yup, that is the question.
 > 
 > Back to the dice... Roll two dice 100 times. Get 100 pieces of paper and
 > write the results of the first die on one side and write the results
 > of the second die on the other side of the piece of paper. Put all the
 > pieces of paper in a hat. Now pick a piece of paper out of the hat.
 > You see a six on the piece of paper, what is the probability that the
 > other side has a six? IT IS 1/11!!!!!!! 
But this is the answer to the other question!  (You throw two dice, one of
them shows a 6, what is the probability that the other also shows a 6.)

The correct analogy is: you throw two dice, the first one you see shows a
6, what is the probability that the other one shows a 6.

The other question can also be put as the next analogy: you throw two dice,
the first one you see shows a 6, and/or the second one you see shows a 6,
what is the probability that both show a 6.
-- 
dik t. winter, cwi, kruislaan 413, 1098 sj  amsterdam, nederland
home: bovenover 215, 1025 jn  amsterdam, nederland; e-mail: dik@cwi.nl