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

It is currently 06 Jul 2015, 06:04

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

Three brothers apply to a certain business school. The

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1607
Followers: 7

Kudos [?]: 87 [0], given: 0

Three brothers apply to a certain business school. The [#permalink] New post 29 Jun 2004, 05:48
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Three brothers apply to a certain business school. The probability of the first one being admitted is 0.9; the second—0.5; the third—0.2. Find the probability that:

1) at least two are admitted
2) at least one is admitted
3) none is admitted
Senior Manager
Senior Manager
avatar
Joined: 26 Jan 2004
Posts: 402
Location: India
Followers: 1

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

 [#permalink] New post 29 Jun 2004, 05:58
1) Atleast two --> 0.9*0.5+0.5*0.2+0.9*0.2+0.9*0.5*0.2 = 0.82
2) Atleast One --> 1 - None --> 1 - (1-0.9)*(1-0.5)(1-0.2) = 1 - 0.1*0.5*0.8 = 0.96
3) None (1-0.9)*(1-0.5)(1-0.2) = 0.04
Senior Manager
Senior Manager
avatar
Joined: 26 Jan 2004
Posts: 402
Location: India
Followers: 1

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

 [#permalink] New post 29 Jun 2004, 06:43
Ya! sure about all three.

Why? is the OA different??
Senior Manager
Senior Manager
User avatar
Joined: 07 Oct 2003
Posts: 358
Location: Manhattan
Followers: 2

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

Re: PS: three brothers--probability [#permalink] New post 29 Jun 2004, 08:31
stolyar wrote:
Three brothers apply to a certain business school. The probability of the first one being admitted is 0.9; the second—0.5; the third—0.2. Find the probability that:

1) at least two are admitted
2) at least one is admitted
3) none is admitted


1) P(2 get in) + P(3 get in)=
.9(.5)*(1-.2)=.36
.9(.2)*(1-.5)=.09
.5(.2)*(1-.9)=.01
.36+.09+.01=.46 -->P2 get in
(mental check, 3C2=3 different ways to get 2 out of three)

P(3 get in) = .9(.5)(.2)=.09

P(2 get in) + P(3 get in) = .55

(from a quick glance, I think MBA forgot to multiply the probabilities of 2 get in by the probability of the 3rd person not getting in, hence his answer was of)

2) P (at least one gets in) = 1 - P(non are admitted)
1- (1-.9)(1-.5)(1-.2) = 1-.04=.96

3)P (none get in) = .04
Re: PS: three brothers--probability   [#permalink] 29 Jun 2004, 08:31
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic The combined salaries of three brothers rango 3 03 Mar 2014, 03:30
6 Experts publish their posts in the topic A certain business school has 500 students, and the law MacFauz 8 10 Nov 2012, 04:30
10 Experts publish their posts in the topic In a business school case competition, the top three teams alchemist009 7 05 Jul 2012, 22:02
Of the students at a certain business school, 60% are GMATT73 10 03 Oct 2005, 06:04
Display posts from previous: Sort by

Three brothers apply to a certain business school. The

  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®.