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

It is currently 18 Sep 2014, 12:24

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

Each of the 25 balls in a certain box is either red, blue,

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 02 Sep 2006
Posts: 256
Followers: 1

Kudos [?]: 11 [0], given: 0

GMAT Tests User
Each of the 25 balls in a certain box is either red, blue, [#permalink] New post 04 Apr 2007, 07:12
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Each of the 25 balls in a certain box is either red, blue, or white and has a number from 1 to 10 painted on it. If one ball is to be selected from the box, what is the probability that the ball selected will either be white or have an even number painted on it.

1. The probability that the ball will both be white and have an even number painted on it is zero.

2. The probability that the ball will be white minus the probability that the ball have an even number painted on it is 0.2
Manager
Manager
User avatar
Joined: 28 Dec 2006
Posts: 62
Followers: 1

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

 [#permalink] New post 04 Apr 2007, 16:04
1. P(A & B) =0

2. P(A) - P(B)=0.2

We cannot find P (A or B) which is equal to P(A) + P(B) {since P(A & B) =0}

Is it E?
Senior Manager
Senior Manager
avatar
Joined: 11 Feb 2007
Posts: 360
Followers: 1

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

GMAT Tests User
 [#permalink] New post 04 Apr 2007, 22:04
Let A = ball selected is white
Let B = ball selected is even

1. The probability that the ball will both be white and have an even number painted on it is zero.

Insuff. We don't know how many odd numbered white balls there are.

2. The probability that the ball will be white minus the probability that the ball have an even number painted on it is 0.2

Insuff. 0.2 can be the results of 0.5 - 0.3, 0.4 - 0.2, etc.

1+2
From 1 we know that P(AnB) = 0
From 2 we know that P(A)-P(B) = 0.2

We need to know P(AuB) which is equal to P(A)+P(B)-P(AnB).
We only know P(AnB) and the difference of P(A) and P(B) where P(A) > P(B). We don't know P(A) and P(B) for sure. So Insuff.

Is the OA E?
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1389
Followers: 2

Kudos [?]: 18 [0], given: 0

GMAT Tests User
 [#permalink] New post 08 Apr 2007, 08:25
Guys in this question

from (I) we have the probablity of white or a even number are indepedent events right ? which means

P(White)*P(Even) = 0

Am I thinking right?
Manager
Manager
avatar
Joined: 28 Feb 2007
Posts: 198
Location: California
Followers: 2

Kudos [?]: 4 [0], given: 0

GMAT Tests User
 [#permalink] New post 08 Apr 2007, 10:46
trivikram wrote:
Guys in this question

from (I) we have the probablity of white or a even number are indepedent events right ? which means

P(White)*P(Even) = 0

Am I thinking right?


No. you are wrong in my opinion. What 1) says is that P(White and Even) is 0. That doesnt meen that events are independent.

P(White)*P(Even) = 0 <=> events are independent.

What do others thinks?
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1389
Followers: 2

Kudos [?]: 18 [0], given: 0

GMAT Tests User
 [#permalink] New post 08 Apr 2007, 11:01
OK

So from (I) we have P(W and E) = 0

So p(PUE) = P(E)+P(W)-P(EandW)

Since we do not know P(E) and P(W)

its E

Am I correct?
  [#permalink] 08 Apr 2007, 11:01
    Similar topics Author Replies Last post
Similar
Topics:
Each of the 25 balls in a certain box is either red, blue, jjhko 1 03 Oct 2008, 19:31
27 Experts publish their posts in the topic Each of the 25 balls in a certain box is either red, blue or lexis 21 01 May 2008, 10:01
Each of the 25 balls in a certain box is either red, blue, positive soul 4 26 Sep 2006, 18:09
Each of 25 balls in a certain box is either red, blue, or GMATT73 13 30 Aug 2006, 02:04
Each of the 25 balls in a certain box are either red, blue jodeci 3 07 Apr 2006, 19:32
Display posts from previous: Sort by

Each of the 25 balls in a certain box is either red, blue,

  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®.