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

It is currently 04 Sep 2015, 12:05
GMAT Club Tests

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

The probability of pulling a black ball out of a glass jar

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 14 Dec 2004
Posts: 117
Followers: 1

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

The probability of pulling a black ball out of a glass jar [#permalink] New post 13 Mar 2005, 13:02
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The probability of pulling a black ball out of a glass jar is 1/X. The probability of pulling a black ball out of a glass jar and breaking the jar is 1/Y. What is the probability of breaking the jar?

a) 1/(XY).
b) X/Y.
c) Y/X.
d) 1/(X+Y).
e) 1/(X-Y).
Manager
Manager
avatar
Joined: 13 Oct 2004
Posts: 236
Followers: 1

Kudos [?]: 9 [0], given: 0

 [#permalink] New post 13 Mar 2005, 14:11
P(A And B) = P(A).P(B|A)

Where P(A) = probability of being black
P(B) = Probabilty of breaking the jar

from the data in the prob, 1/y = (1/x) * P(B|A) = x/y.

Not sure if this is the right approach for this problem. As x/y gives the probability of breaking the jar given that a black ball is drawn from the jar.
VP
VP
User avatar
Joined: 13 Jun 2004
Posts: 1119
Location: London, UK
Schools: Tuck'08
Followers: 7

Kudos [?]: 33 [0], given: 0

 [#permalink] New post 13 Mar 2005, 16:22
B too, same approach as prep_gmat
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5067
Location: Singapore
Followers: 24

Kudos [?]: 215 [0], given: 0

 [#permalink] New post 13 Mar 2005, 23:03
Let A denote P(pulling black ball out of glass jar)= 1/x
B denote P(black ball out of glass jar and breaking jar) = 1/y
C denote P(breaking glass jar)

A AND C = B
(1/x)(C) = 1/y
(C) = x/y
Director
Director
User avatar
Joined: 21 Sep 2004
Posts: 612
Followers: 1

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

 [#permalink] New post 14 Mar 2005, 06:23
P(A and B) = P(A).P(B)
X/Y

Last edited by vprabhala on 14 Mar 2005, 09:56, edited 1 time in total.
VP
VP
avatar
Joined: 18 Nov 2004
Posts: 1441
Followers: 2

Kudos [?]: 23 [0], given: 0

 [#permalink] New post 14 Mar 2005, 08:22
"B"

I think pulling a ball and breaking the jar r independent events so I don't think P(A|B) applies here.

For independent events:

P(A and B) = P(A).P(B)

1/Y = 1/X.P(B)


P(B) = X/Y
Manager
Manager
avatar
Joined: 15 Feb 2005
Posts: 246
Location: Rockville
Followers: 1

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

 [#permalink] New post 14 Mar 2005, 11:12
X/y
prob of Blakc ball and Breaking jar= Prob of Black ball*prob of breaking jar=1/y
  [#permalink] 14 Mar 2005, 11:12
Display posts from previous: Sort by

The probability of pulling a black ball out of a glass jar

  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®.