Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 21 May 2013, 04:48
Customize  |  Hide

Search
Register
New posts
Unanswered

The probability that a student will pass in Math is 3/5 and

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Manager
Manager
Joined: 28 Aug 2004
Posts: 206
Followers: 1

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

GMAT Tests User
The probability that a student will pass in Math is 3/5 and [#permalink] New post 16 Jun 2005, 09:56
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
The probability that a student will pass in Math is 3/5 and the probability that he will pass in English is 1/3. If the probability that he will pass in both Math and English is 1/8, what is the probability that he will pass in at least one subject?
VP
VP
Joined: 27 Dec 2004
Posts: 1089
Followers: 1

Kudos [?]: 5 [0], given: 0

GMAT Tests User
 [#permalink] New post 16 Jun 2005, 10:44
7/8

but hsouldn't the probability of passing both math and englush be 1/5 instead of 1/8 ?
Senior Manager
Senior Manager
Joined: 30 May 2005
Posts: 374
Followers: 1

Kudos [?]: 5 [0], given: 0

GMAT Tests User
 [#permalink] New post 16 Jun 2005, 10:56
Folaa3 wrote:
7/8

but hsouldn't the probability of passing both math and englush be 1/5 instead of 1/8 ?
Assume that there are 120 students (120 is the LCM of 3,5 and 8)

No of students who passed Math = (3/5)*120 = 72
No of students who passed English = (1/3)*120 = 40
No of students who passed both, which by the way is not calculable from the above = (1/8)*120 = 15
So, the number of students who passed either Math or English or both = 72+40 - 15 = 97
QED.
Manager
Manager
Joined: 05 May 2005
Posts: 93
Location: Kyiv, Ukraine
Followers: 1

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

 [#permalink] New post 16 Jun 2005, 11:00
what about people who will pass neither one? does the problem exclude them?
VP
VP
Joined: 27 Dec 2004
Posts: 1089
Followers: 1

Kudos [?]: 5 [0], given: 0

GMAT Tests User
 [#permalink] New post 16 Jun 2005, 11:20
AJB77 wrote:
Folaa3 wrote:
7/8

but hsouldn't the probability of passing both math and englush be 1/5 instead of 1/8 ?
Assume that there are 120 students (120 is the LCM of 3,5 and 8)

No of students who passed Math = (3/5)*120 = 72
No of students who passed English = (1/3)*120 = 40
No of students who passed both, which by the way is not calculable from the above = (1/8)*120 = 15
So, the number of students who passed either Math or English or both = 72+40 - 15 = 97
QED.


i see what you are saying but my point is, if the question stem says 3/5 passed maths and 1/3 passed english,
then the prob of those who pass both math and english should be
1/3 * 3/5 = 3/15 = 1/5
Unless the stem is implying information that is not given. How can the prob of both be 1/8.
Senior Manager
Senior Manager
Joined: 30 May 2005
Posts: 374
Followers: 1

Kudos [?]: 5 [0], given: 0

GMAT Tests User
 [#permalink] New post 16 Jun 2005, 11:47
Folaa3 wrote:
i see what you are saying but my point is, if the question stem says 3/5 passed maths and 1/3 passed english,
then the prob of those who pass both math and english should be
1/3 * 3/5 = 3/15 = 1/5
Unless the stem is implying information that is not given. How can the prob of both be 1/8.


3/5 passed Math could mean that all of the 3/5 passed English as well or none of them passed English.

Let me give you an example:

Let's say we have 6 people, 1 passed Math alone, 1 passed English alone, 2 passed both and 2 failed both

Now if I ask you, How many students passed Math? Will you say 1 or 3?

Similarly, how many students passed English?

Think about it.
SVP
SVP
User avatar
Joined: 03 Jan 2005
Posts: 2322
Followers: 9

Kudos [?]: 157 [0], given: 0

GMAT Tests User
 [#permalink] New post 16 Jun 2005, 13:10
Folaa3, 7/8 is the possibility that the student fail at least one subject (vs pass at least one subject). (Also, there is only one student in this case, although not important.)

Passing English test and Math test are not independent, you can't simply multiply the possibilities together and say P(A&B)=P(A)*P(B).
_________________

Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.

  [#permalink] 16 Jun 2005, 13:10
    Similar topics Author Replies Last post
Similar
Topics:
 Popular new posts 1-The probability of passing test A is a, The probability of Praetorian 11 07 Dec 2003, 22:39
New posts 35 - Probability Guest 5 11 Nov 2004, 03:34
New posts GMAT Math - Probability peterpan 4 18 Dec 2004, 20:20
Popular new posts 62 EXPERTS_POSTS_IN_THIS_TOPIC Math: Probability walker 59 23 Nov 2009, 22:17
New posts Math question probability nailgmattoefl 3 28 Dec 2009, 11:53
Display posts from previous: Sort by

The probability that a student will pass in Math is 3/5 and

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma, IanStewart

Search for:


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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com