|
Author |
Message |
|
TAGS:
|
|
|
Director
Joined: 03 Jul 2003
Posts: 716
Followers: 2
Kudos [?]:
4
[0], given: 0
|
There is a family with two children. One is a boy, what is [#permalink]
 15 Feb 2004, 00:35
There is a family with two children. One is a boy, what is the
probability that the other is a girl?
|
|
|
|
|
|
|
GMAT Club Legend
Joined: 15 Dec 2003
Posts: 4441
Followers: 10
Kudos [?]:
82
[0], given: 0
|
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
_________________
Best Regards,
Paul
|
|
|
|
|
|
SVP
Joined: 30 Oct 2003
Posts: 1963
Location: NewJersey USA
Followers: 3
Kudos [?]:
25
[0], given: 0
|
I stand by Paul on this one.
Hi Paul,
By any chance r u registered at TestMagic as Paul78 ?
Anand.
|
|
|
|
|
|
Director
Joined: 03 Jul 2003
Posts: 716
Followers: 2
Kudos [?]:
4
[0], given: 0
|
Paul wrote: 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.
|
|
|
|
|
|
SVP
Joined: 30 Oct 2003
Posts: 1963
Location: NewJersey USA
Followers: 3
Kudos [?]:
25
[0], given: 0
|
Then what we have is
BG GB GG BB
so dsired events are BG and GB total events are 4
2/4 = 1/2
|
|
|
|
|
|
Director
Joined: 03 Jul 2003
Posts: 716
Followers: 2
Kudos [?]:
4
[0], given: 0
|
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!
|
|
|
|
|
|
GMAT Club Legend
Joined: 15 Dec 2003
Posts: 4441
Followers: 10
Kudos [?]:
82
[0], given: 0
|
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! 
_________________
Best Regards,
Paul
|
|
|
|
|
|
GMAT Instructor
Joined: 07 Jul 2003
Posts: 773
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 5
Kudos [?]:
9
[0], given: 0
|
kpadma wrote: 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.
_________________
Best,
AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993
|
|
|
|
|
|
Director
Joined: 03 Jul 2003
Posts: 716
Followers: 2
Kudos [?]:
4
[0], given: 0
|
AkamaiBrah wrote: 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. Yes, Adding "atleast" makes the question clearer.
Thanks Akamai!
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Similar topics |
Author |
Replies |
Last post |
|
Similar
Topics:
|
 |
|
|
What is the probability for a family with three children to
|
gmatacer |
6 |
17 Apr 2006, 06:45 |
|
|
|
|
A family consisting of one mother, one father, two daughters
|
sujayb |
9 |
22 Nov 2006, 13:50 |
|
|
|
|
A family consisting of one mother, one father, two daughters
|
gmatkudi |
4 |
01 Sep 2008, 22:30 |
|
|
6
|
 |
A family consisting of one mother, one father, two daughters
|
pratikbais |
5 |
27 Apr 2012, 03:57 |
|
|
1
|
|
The Coen family consists of a father, a mother, two children
|
Joy111 |
4 |
30 May 2012, 22:13 |
|
|
|
|
|
|
close
