GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 27 Jun 2019, 01:34

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

The probability that a family with 6 children has exactly

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Intern
Intern
avatar
B
Joined: 29 Dec 2014
Posts: 24
Schools: IMD '21 (S)
GMAT ToolKit User
Re: The probability that a family with 6 children has exactly  [#permalink]

Show Tags

New post 09 Sep 2018, 07:44
C as 15 favorable and each position can take 2 either boy or girl so we have 6 position i.e 64

Posted from my mobile device
Intern
Intern
avatar
B
Joined: 12 Jun 2018
Posts: 17
Re: The probability that a family with 6 children has exactly  [#permalink]

Show Tags

New post 10 Sep 2018, 02:02
I have a doubt e.g: question i-3 m and 5 women. We need to select 5 people . P(2 are men)

So i do Total outcomes 8C2 Favorable 3c2* 5c3 ans= fav/total.

Here in this question if they have asked me P of exactly 4 boys. shouldn't Favorable Outcomes be equal to --->be 6c4(boys)*6c2(if not boys then girls)

Need guidance on what the difference int he given question and a assumed question i mentioned above.

Thanks in advance

Bunuel wrote:
ashueureka wrote:
I think this way:

For each child we've two options i.e., that child can either be a boy or a girl.Hence we have 2^6 = 64 total outcomes.
Now out of 6 children any 4 of them can boys and this can be done in 6C4 = 15 ways.
Now here I don't think that ordering does matter in this case.

So the probability comes out to be 15/64.

P.S. Please explain me if ordering really matters in this case as my understanding is quite naive in these problems.


This way of solving is also correct. You've already considered all possible arrangements for BBBBGG with 6C4, which is 6!/4!2!. If you look at my solution and at yours you'll see that both wrote the same formulas but with different approach.
CEO
CEO
User avatar
P
Joined: 18 Aug 2017
Posts: 3947
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member CAT Tests
Re: The probability that a family with 6 children has exactly  [#permalink]

Show Tags

New post 21 Jun 2019, 10:48
GMATMadeeasy wrote:
The probability that a family with 6 children has exactly four boys is:

A. 1/3
B. 1/64
C. 15/64
D. 3/8
E. none of the above


either boy or girl = 1/2 and for 6 ; 1/2^6 ; 1/64
and exactly 4 boys ; 6!/4!*2! ; 15
IMO C ; 15/64
_________________
If you liked my solution then please give Kudos. Kudos encourage active discussions.
GMAT Club Bot
Re: The probability that a family with 6 children has exactly   [#permalink] 21 Jun 2019, 10:48

Go to page   Previous    1   2   [ 23 posts ] 

Display posts from previous: Sort by

The probability that a family with 6 children has exactly

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne