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

It is currently 18 Sep 2014, 20:33

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

Set S consists of all prime integers less than 10. If a

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Current Student
User avatar
Joined: 11 May 2008
Posts: 559
Followers: 7

Kudos [?]: 22 [0], given: 0

GMAT Tests User
Set S consists of all prime integers less than 10. If a [#permalink] New post 04 Sep 2008, 01:35
1
This post was
BOOKMARKED
Set S consists of all prime integers less than 10. If a number is selected from set S at random and then another number, not necessarily different, is selected from set S at random, what is the probability that the sum of these numbers is odd?


* \frac{1}{8}
* \frac{1}{6}
* \frac{3}{8}
* \frac{1}{2}
* \frac{5}{8}
Current Student
User avatar
Joined: 04 Jan 2005
Posts: 283
Location: Milan
Schools: Wharton, LBS, UChicago, Kellogg MMM (Donald Jacobs Scholarship), Stanford, HBS
Followers: 6

Kudos [?]: 134 [0], given: 3

GMAT Tests User
Re: probability [#permalink] New post 04 Sep 2008, 01:57
3/8

Set S: 2, 3, 5, 7

Total cases: 4^2 = 16

First number 2: 1 case even (2,2), 3 cases odd (2,3 ; 2,5; 2,7)
First number odd (3 or 5 or 7): 3 cases even, 1 case odd

To sum it up:

EVEN: 1 + 3*3 = 10 out of 16
ODD: 3 + 1*3 = 6 out of 16

Pr(odd): 6/16 = 3/8
SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1829
Location: New York
Followers: 27

Kudos [?]: 451 [0], given: 5

GMAT Tests User
Re: probability [#permalink] New post 04 Sep 2008, 06:38
arjtryarjtry wrote:
Set S consists of all prime integers less than 10. If a number is selected from set S at random and then another number, not necessarily different, is selected from set S at random, what is the probability that the sum of these numbers is odd?


* \frac{1}{8}
* \frac{1}{6}
* \frac{3}{8}
* \frac{1}{2}
* \frac{5}{8}


2,3,5,7 -- First selection set
2,3,5,7-- second selection set

to get the odd.. sum odd+even.

=(select 2 from 1st set * select any odd number from 2nd set) +(select 2 from 2st set * select any odd number from 1st set)
= 1*3+1*3 =6

p= 6/4*4 = 3/8
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning


Last edited by x2suresh on 04 Sep 2008, 07:05, edited 1 time in total.
VP
VP
User avatar
Joined: 05 Jul 2008
Posts: 1436
Followers: 33

Kudos [?]: 217 [0], given: 1

GMAT Tests User
Re: probability [#permalink] New post 04 Sep 2008, 06:54
x2suresh wrote:
arjtryarjtry wrote:
Set S consists of all prime integers less than 10. If a number is selected from set S at random and then another number, not necessarily different, is selected from set S at random, what is the probability that the sum of these numbers is odd?


* \frac{1}{8}
* \frac{1}{6}
* \frac{3}{8}
* \frac{1}{2}
* \frac{5}{8}


2,3,5,7 -- First selection set
2,3,5,7-- second selection set

to get the odd.. sum odd+even.

=(select 2 from 1st set * select any odd number from 2nd set) +(select 2 from 1st set * select any odd number from 2nd set)
= 1*3+1*3 =6

p= 6/4*4 = 3/8


I believe you wanted to write
(select 2 from 1st set * select any odd number from 2nd set) +(select 2 from 2nd set * select any odd number from 1st set
Re: probability   [#permalink] 04 Sep 2008, 06:54
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic Set S consists of all prime integers less than 10. If two ashiima 5 15 Dec 2011, 17:56
2 Set S consists of all prime integers less than 10. If a bipolarbear 3 10 Aug 2009, 07:52
1 Set S consists of all prime integers less than 10. If a amitdgr 9 30 Oct 2008, 03:42
Set S consists of all prime integers less than 10. If a arjtryarjtry 4 09 Sep 2008, 10:07
Set S consists of all prime integers less than 10. If two beckee529 3 29 Oct 2007, 22:49
Display posts from previous: Sort by

Set S consists of all prime integers less than 10. If a

  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®.