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kpadma
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There is a family with two children. One is a boy, what is 15 Feb 2004, 00:35
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There is a family with two children. One is a boy, what is the
probability that the other is a girl?



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Paul
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There is a family with two children. One is a boy, what is 15 Feb 2004, 00:54
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1/2 if the fact that the first kid being a boy is independent of the second kid being a girl
1/4 if the question is about the probability of having first kid a boy and second kid a girl
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There is a family with two children. One is a boy, what is 15 Feb 2004, 06:30
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I stand by Paul on this one.

Hi Paul,

By any chance r u registered at TestMagic as Paul78 ?

Anand.
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kpadma
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There is a family with two children. One is a boy, what is 15 Feb 2004, 07:10
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Paul
1/2 if the fact that the first kid being a boy is independent of the second kid being a girl
1/4 if the question is about the probability of having first kid a boy and second kid a girl


Sex of any baby is indepedent of its siblings.
Question stem does not say the first baby is boy.
All it says is one is boy.
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There is a family with two children. One is a boy, what is 15 Feb 2004, 07:40
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Then what we have is

BG GB GG BB
so dsired events are BG and GB total events are 4
2/4 = 1/2
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kpadma
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There is a family with two children. One is a boy, what is 15 Feb 2004, 08:07
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I don't have official answer.

But, here is my explanation.

Total possibilities = BB, GG, BG, GB
One(Atleast) is BOY = BB, BG, GB
Another is Girl,given than other is BOY = BG , GB

P = 2/3.

As i said before, I don't have official answer!
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There is a family with two children. One is a boy, what is 15 Feb 2004, 10:11
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interesting reasoning kpadma. Indeed, you would then have to remove GG to get 2/3. I think it should be right then. Anandnk, yes i'm paul78 on testmagic. Put the same signature so that you could recognize me... you stalker! :maniac
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There is a family with two children. One is a boy, what is 17 Feb 2004, 07:29
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kpadma
I don't have official answer.

But, here is my explanation.

Total possibilities = BB, GG, BG, GB
One(Atleast) is BOY = BB, BG, GB
Another is Girl,given than other is BOY = BG , GB

P = 2/3.

As i said before, I don't have official answer!


The question should be worded "at least one is a boy" and in that case, 2/3 is the answer. Trust me.

However, as worded, the question states: "ONE is a boy". hence the other child MUST be a girl. If the other was a boy, then the statement "ONE is a boy" would not be true -- because in that case TWO of them are boys!

Of course, this is an oversight and the GMAT would not be so ambiguous.

:twisted:
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There is a family with two children. One is a boy, what is 17 Feb 2004, 08:26
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AkamaiBrah
The question should be worded "at least one is a boy" and in that case, 2/3 is the answer. Trust me.

However, as worded, the question states: "ONE is a boy". hence the other child MUST be a girl. If the other was a boy, then the statement "ONE is a boy" would not be true -- because in that case TWO of them are boys!

Of course, this is an oversight and the GMAT would not be so ambiguous.

:twisted:


Yes, Adding "atleast" makes the question clearer.
Thanks Akamai!



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