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

It is currently 29 Jul 2015, 21:02
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
Director
Director
avatar
Joined: 22 Aug 2007
Posts: 569
Followers: 1

Kudos [?]: 17 [0], given: 0

The probability of pulling a black ball out of a glass jar [#permalink] New post 22 Sep 2007, 08:31
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).
VP
VP
avatar
Joined: 10 Jun 2007
Posts: 1463
Followers: 6

Kudos [?]: 146 [0], given: 0

Re: combination_break it [#permalink] New post 22 Sep 2007, 08:55
IrinaOK wrote:
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).


I got b
P(black)=1/x
P(break and black)=1/y=P(black)xP(break)
P(break)= x/y
Director
Director
avatar
Joined: 11 Jun 2007
Posts: 932
Followers: 1

Kudos [?]: 83 [0], given: 0

Re: combination_break it [#permalink] New post 22 Sep 2007, 08:57
IrinaOK wrote:
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).


A = probability of pulling a black ball out of a glass jar 1/X
B = probability of breaking the jar
C = pulling a black ball out of a glass jar and breaking the jar 1/Y

A * B = C

solve for B: B = C / A
B = (1/Y) / (1/X)
B = X /Y (answer B)
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3387
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 14

Kudos [?]: 191 [0], given: 2

 [#permalink] New post 22 Sep 2007, 09:05
i got B too...

prob of pulling ball 1/x

prob of breaking jar 1/n

prob of pulling ball AND breaking jar 1/y

1/x * 1/n =1/y

1/n=x/y
  [#permalink] 22 Sep 2007, 09:05
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®.