It is currently 14 Dec 2017, 13:16

Decision(s) Day!:

CHAT Rooms | Wharton R1 | Stanford R1 | Tuck R1 | Ross R1 | Haas R1 | UCLA R1


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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

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

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Senior Manager
Senior Manager
User avatar
Joined: 25 Dec 2003
Posts: 358

Kudos [?]: 37 [0], given: 0

Location: India
A box contains 7 Yellow balls and 5 blue balls. Select 3 [#permalink]

Show Tags

New post 12 Jul 2004, 06:48
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

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

Kudos [?]: 37 [0], given: 0

Senior Manager
Senior Manager
avatar
Joined: 05 Feb 2004
Posts: 290

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

Location: USA
 [#permalink]

Show Tags

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!!

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

Director
Director
avatar
Joined: 04 Jul 2004
Posts: 893

Kudos [?]: 68 [0], given: 0

 [#permalink]

Show Tags

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)

Kudos [?]: 68 [0], given: 0

Joined: 31 Dec 1969

Kudos [?]: [0], given:

Location: Russian Federation
Concentration: Entrepreneurship, International Business
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 9: 740 Q49 V42
GMAT 11: 500 Q47 V33
GMAT 14: 760 Q49 V44
WE: Supply Chain Management (Energy and Utilities)
 [#permalink]

Show Tags

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.

Kudos [?]: [0], given:

  [#permalink] 12 Jul 2004, 10:45
Display posts from previous: Sort by

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

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderator: chetan2u



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

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

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®.