What is the probability for a family with three children to

Oldest

Best Reply

Author

Message

TAGS:

Senior Manager

Joined: 24 Jan 2006

Posts: 256

Followers: 1

Kudos [?]: 2 [0], given: 0

What is the probability for a family with three children to [#permalink]

17 Apr 2006, 06:45

26. What is the probability for a family with three children to have a boy and two girls (assuming the probability of having a boy or a girl is equal)?

a) 1/8
b) Â¼
c) Â½
d) 3/8
e) 5/8

Intern

Joined: 15 Apr 2006

Posts: 23

Followers: 0

Kudos [?]: 1 [0], given: 0

[#permalink]

17 Apr 2006, 07:29

My solution:

BGG : 1/2 * 1/2 * 1/2 = 1/8
GBG: 1/8
GGB: 1/8

So the probability is 3/8 which is the same as BG

BG can U explain your solution, I dont think I get it

Director

Joined: 13 Nov 2003

Posts: 811

Location: BULGARIA

Followers: 1

Kudos [?]: 6 [0], given: 0

[#permalink]

17 Apr 2006, 07:43

This is the binominal formula, which gives all possible outcomes.
prob 3b=1/8
prob 2b1g=3/8
prob2g1b=3/8
prob 3g=1/8
when you sum up this you get 1

Senior Manager

Joined: 08 Sep 2004

Posts: 259

Location: New York City, USA

Followers: 1

Kudos [?]: 5 [0], given: 0

[#permalink]

17 Apr 2006, 08:40

I think it is B, 1/4.

A family with 3 children can have either

BBB
BBG
BGG
GGG

Only one out of four is the required combination.

- Vipin

Senior Manager

Joined: 08 Sep 2004

Posts: 259

Location: New York City, USA

Followers: 1

Kudos [?]: 5 [0], given: 0

[#permalink]

17 Apr 2006, 09:04

vipin7um wrote:

I think it is B, 1/4.

A family with 3 children can have either

BBB
BBG
BGG
GGG

Only one out of four is the required combination.

- Vipin

No this wouldn't be. The correct answer is 3/8.

Thanks,
Vipin

Manager

Joined: 20 Mar 2005

Posts: 203

Location: Colombia, South America

Followers: 1

Kudos [?]: 2 [0], given: 0

Re: P&C - 3 [#permalink]

17 Apr 2006, 18:55

gmatacer wrote:

26. What is the probability for a family with three children to have a boy and two girls (assuming the probability of having a boy or a girl is equal)?

a) 1/8
b) Â¼
c) Â½
d) 3/8
e) 5/8

X= # of girls

P(X=2) when n=3

P(x=2) = 3c2 * (1/2)^2 * 1/2

= 3/8

Manager

Joined: 08 Feb 2006

Posts: 128

Followers: 1

Kudos [?]: 0 [0], given: 0

[#permalink]

17 Apr 2006, 23:18

I have trouble finding the p in the binominal formula. How did you find p to be 1/2?

[#permalink] 17 Apr 2006, 23:18

		Similar topics	Author	Replies	Last post
Similar Topics:		Three fair dice are rolled together. What is the probability	stolyar	1	21 Jun 2003, 02:33
		A couple has 4 children, what is the probability that they	Praetorian	4	13 Sep 2003, 20:00
		There is a family with two children. One is a boy, what is	kpadma	8	15 Feb 2004, 00:35
	1	The probability that a family with 6 children has exactly	GMATMadeeasy	14	08 Jan 2010, 17:56
		Family with three children	petrifiedbutstanding	2	06 Feb 2011, 02:20

What is the probability for a family with three children to

Main navigation

GMAT Resources

Partners

MBA Resources

GMAT ® is a registered trademark of the Graduate Management Admission Council ® (GMAC ®). GMAT Club's website has not been reviewed or endorsed by GMAC.

GMAT Courses

Admissions Consulting

What is the probability for a family with three children to

What is the probability for a family with three children to

Main navigation

GMAT Resources

Partners

MBA Resources