Find all School-related info fast with the new School-Specific MBA Forum

It is currently 29 Aug 2014, 06:48

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A box contains 7 Yellow balls and 5 blue balls. Select 3

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 25 Dec 2003
Posts: 360
Location: India
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
A box contains 7 Yellow balls and 5 blue balls. Select 3 [#permalink] New post 12 Jul 2004, 06:48
A box contains 7 Yellow balls and 5 blue balls. Select 3 balls randomly. What is the probability of choosing 3 blue ones.

explain steps please.
_________________

Giving another SHOT

Senior Manager
Senior Manager
avatar
Joined: 05 Feb 2004
Posts: 291
Location: USA
Followers: 1

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

GMAT Tests User
 [#permalink] New post 12 Jul 2004, 07:45
3 balls can be chosen from 12 in : 12C3 ways
3 blue balls can be chosen from 5 blues in: 5C3 ways

Hence required prob: 5C3/12C3 = 10/220 = 1/22!!
Director
Director
avatar
Joined: 04 Jul 2004
Posts: 905
Followers: 3

Kudos [?]: 19 [0], given: 0

GMAT Tests User
 [#permalink] New post 12 Jul 2004, 07:46
Probability = (Fav. outcome) / (Total Outcome)

Total : selecting 3 balls from 12 balls = 12C3
Favourable : selecting 3 blue from 5 blue balls = 5C3

P = 5C3 / 12C3 (Very lengthy calculation)
Joined: 31 Dec 1969
Location: United States
Concentration: Marketing, Other
GMAT 1: 710 Q49 V38
GMAT 2: 660 Q V
GPA: 3.64
WE: Accounting (Accounting)
Followers: 0

Kudos [?]: 60 [0], given: 76305

 [#permalink] New post 12 Jul 2004, 10:45
I would do:

5/12 x 4/11 x 3/10 = 1/22 and forget about the combinations formula.
  [#permalink] 12 Jul 2004, 10:45
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic A box contains 3 yellow balls and 5 black balls. One by one gmativy 2 08 Dec 2010, 18:20
14 Experts publish their posts in the topic A box contains 3 yellow balls and 5 black balls. One by one dmetla 16 09 Feb 2010, 21:00
18 Experts publish their posts in the topic A box contains 3 yellow balls and 5 black balls. One by one tejal777 22 29 Sep 2009, 00:14
There are 3 green; 4 yellow; and 5 blue balls in a sack. 6 ggarr 3 06 Feb 2007, 22:35
There are 5 blue balls and 7 red balls in the 1st box and 11 inga 6 18 Mar 2005, 11:21
Display posts from previous: Sort by

A box contains 7 Yellow balls and 5 blue balls. Select 3

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.