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

It is currently 21 Dec 2014, 22:19

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

7 cars compete in a race and finish at different times. find

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 61

Kudos [?]: 683 [0], given: 781

7 cars compete in a race and finish at different times. find [#permalink] New post 14 Sep 2003, 12:31
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
7 cars compete in a race and finish at different times. find the probability that prat who drives the blue car finishes ahead of martin who drives a red car?
GMAT Instructor
User avatar
Joined: 07 Jul 2003
Posts: 771
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 13

Kudos [?]: 39 [0], given: 0

Re: PS : Probability # 3 [#permalink] New post 14 Sep 2003, 19:47
praetorian123 wrote:
7 cars compete in a race and finish at different times. find the probability that prat who drives the blue car finishes ahead of martin who drives a red car?


Since there is no difference in the cars, each car will be equally likely to be ahead of the other.

1/2.
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Intern
Intern
avatar
Joined: 12 Sep 2003
Posts: 31
Location: Peru
Followers: 0

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

Re: PS : Probability # 3 [#permalink] New post 14 Sep 2003, 20:12
But I think the statement is about one particular car finishing ahead of another specific car from the group so, the number of events is 6 and the total number of classifications would be 7!, therefore the answer may be
6/7! = 1/840

Am I right?
Intern
Intern
avatar
Joined: 12 Sep 2003
Posts: 31
Location: Peru
Followers: 0

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

 [#permalink] New post 14 Sep 2003, 21:34
No, I'm not. I apologize, I got awfully confused.
Intern
Intern
avatar
Joined: 11 Jul 2003
Posts: 28
Followers: 0

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

 [#permalink] New post 16 Sep 2003, 11:50
It should be 2/7*1/2 = 2/14 = 1/7

P of selecting 2 cars from 7 and P of each of the two being ahead of the other.
Senior Manager
Senior Manager
User avatar
Joined: 22 May 2003
Posts: 334
Location: Uruguay
Followers: 1

Kudos [?]: 24 [0], given: 0

 [#permalink] New post 16 Sep 2003, 19:16
I agree with Akamaibrah, 1/2

From all the posible 7! outcomes of the race, one specific car will be ahead of other specific car the same number of times since all have the same prob.

Although I would assign a higher probability of winning to the other car since "martin" is driving. :wink:
SVP
SVP
User avatar
Joined: 30 Oct 2003
Posts: 1797
Location: NewJersey USA
Followers: 4

Kudos [?]: 40 [0], given: 0

 [#permalink] New post 18 Jan 2004, 10:09
I cannot digest akamaibrah logic. I hope he will explain it.

I get 1/2

There 7 postions so there 7! ways
if you fix the postions of martin and prat then you have

5! * ( 6+5+4+3+2+1 ) = 21 * 5!

so P = 21 * 5! / 7! = 21/42 = 1/2
Intern
Intern
User avatar
Joined: 01 Dec 2003
Posts: 35
Location: infront of my LCD
Followers: 0

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

 [#permalink] New post 18 Jan 2004, 22:09
I've seen this type of question before and the best explanation for 1/2 is out of all the possible scenarios, half the time one finishes ahead of the other and half the time it's the other way around. Dont know if that makes sense.
  [#permalink] 18 Jan 2004, 22:09
    Similar topics Author Replies Last post
Similar
Topics:
5 Experts publish their posts in the topic Five people are running in a race. The first one to finish iwillcrackgmat 8 13 Mar 2012, 19:15
8 Experts publish their posts in the topic A coin is tossed 7 times. Find the probability of getting morya003 5 07 Jan 2012, 12:47
1 Experts publish their posts in the topic A Car comes with 7 different possible exterior colors and 6 gmatpapa 5 10 Feb 2011, 11:49
5 Experts publish their posts in the topic Fifteen runners from four different countries are competing Marco83 12 20 Dec 2009, 14:18
Bob ran a 20 mile race. At what time did he finish the race? bewakoof 18 06 Mar 2006, 13:41
Display posts from previous: Sort by

7 cars compete in a race and finish at different times. find

  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®.