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

It is currently 08 Feb 2016, 00:36
GMAT Club Tests

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

The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 22 Sep 2007
Posts: 34
Followers: 0

Kudos [?]: 2 [0], given: 0

The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or [#permalink] New post 14 Oct 2007, 15:58
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or more numbers over 10. If one number from S1 and one number from S2 are selected randomly, what is the probability that the set selected will have one number over 10 and one number under 10?

a) 3/16
b) 3/8
c) 7/16
d) 1/2
e) 5/8
Manager
Manager
avatar
Joined: 19 Aug 2007
Posts: 169
Followers: 1

Kudos [?]: 29 [0], given: 0

 [#permalink] New post 14 Oct 2007, 17:37
yes D

first case is where the num from S1 is over 10 and the number from S2 is under 10 => probability = 2/4 * 3/4 = 3/8

second case is where the num from S1 is under 10 and the num selected from S2 is over 10 => probability = 2/4 * 1/4 = 1/8

and you add these two cases up to get 3/8 + 1/8 = 1/2
CEO
CEO
User avatar
Joined: 29 Mar 2007
Posts: 2584
Followers: 17

Kudos [?]: 304 [0], given: 0

Re: Probability [#permalink] New post 15 Oct 2007, 00:01
inwosu wrote:
The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or more numbers over 10. If one number from S1 and one number from S2 are selected randomly, what is the probability that the set selected will have one number over 10 and one number under 10?

a) 3/16
b) 3/8
c) 7/16
d) 1/2
e) 5/8



D.

1/2*3/4 = 3/8

1/2*1/4 = 1/8. 1-3/8-1/8 ---> 1/2
Director
Director
User avatar
Joined: 31 Mar 2007
Posts: 585
Location: Canada eh
Followers: 7

Kudos [?]: 53 [0], given: 0

 [#permalink] New post 15 Oct 2007, 15:51
you can reword this problem

what's the probability that you get a number over 10 and one under == 100% - what's the probability that both numbers are under or over 10?

which is easy

1 - 3/8 - 1/8 = 1-4/8 = 1/2
Director
Director
avatar
Joined: 22 Aug 2007
Posts: 567
Followers: 1

Kudos [?]: 27 [0], given: 0

Re: Probability [#permalink] New post 15 Oct 2007, 16:08
inwosu wrote:
The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or more numbers over 10. If one number from S1 and one number from S2 are selected randomly, what is the probability that the set selected will have one number over 10 and one number under 10?

a) 3/16
b) 3/8
c) 7/16
d) 1/2
e) 5/8



D

1/2 x 3/4 + 1/4 x 1/2=1/2
Re: Probability   [#permalink] 15 Oct 2007, 16:08
Display posts from previous: Sort by

The sets S1={15,9,20,7} and S2= {6,11,5,4} both have one or

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.