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

It is currently 22 Oct 2014, 04:53

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

In a group of 800 people, 1/5 play at least one instrument..

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 30 Jun 2012
Posts: 8
Followers: 0

Kudos [?]: 6 [0], given: 1

In a group of 800 people, 1/5 play at least one instrument.. [#permalink] New post 05 Aug 2012, 07:00
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

76% (02:06) correct 24% (01:37) wrong based on 83 sessions
In a group of 800 people, 1/5 play at least one instrument, 96 play two or more. What is the probability that one student play exactly one instrument?

A) 2/125
B) 3/125
C)2/25
D) 3/25
E) 1/5
[Reveal] Spoiler: OA

Last edited by ferrarih on 05 Aug 2012, 15:58, edited 2 times in total.
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23369
Followers: 3607

Kudos [?]: 28758 [1] , given: 2846

Re: In a group with 800 people... [#permalink] New post 05 Aug 2012, 07:08
1
This post received
KUDOS
Expert's post
ferrarih wrote:
In a grouup of 800 people, 1/5 play at least one instrument, 96 play two or more. Whats it is e probability that one student play exactly one instrument?

A) 2/125
B) 3/125
C)2/25
D) 3/25
E) 1/5


Given that 1/5*800=160 students play 1 or more instrument and 96 play 2 or more, so 160-96=64 students play exactly 1 instrument.

Therefore the probability that a randomly chosen student plays exactly one instrument is 64/800=2/25.

Answer: C.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 612
WE: Science (Education)
Followers: 73

Kudos [?]: 529 [0], given: 43

Re: In a group with 800 people... [#permalink] New post 05 Aug 2012, 07:14
ferrarih wrote:
In a grouup of 800 people, 1/5 play at least one instrument, 96 play two or more. Whats it is e probability that one student play exactly one instrument?

A) 2/125
B) 3/125
C)2/25
D) 3/25
E) 1/5


P(playing 2 or more instruments) = 96/800 = 3/25.
Then, the probability of playing exactly one instrument is given by:
P(playing 1 or more instruments) - P(playing 2 or more instruments) = 1/5 - 3/25 = 2/25.

Answer C.
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23369
Followers: 3607

Kudos [?]: 28758 [0], given: 2846

Re: In a group of 800 people, 1/5 play at least one instrument.. [#permalink] New post 13 Jul 2013, 23:11
Expert's post
Re: In a group of 800 people, 1/5 play at least one instrument..   [#permalink] 13 Jul 2013, 23:11
    Similar topics Author Replies Last post
Similar
Topics:
3 Experts publish their posts in the topic 800socre group question marijose 7 13 Mar 2011, 17:41
Experts publish their posts in the topic Can someone score 800 even with at least one wrong answer? rishabhsingla 2 28 Aug 2010, 11:15
28 Experts publish their posts in the topic Of a group of people, 10 play piano, 11 play guitar, 14 play slingfox 40 30 Oct 2009, 20:32
In my class, everyone plays at least one sport. There are 99 devilmirror 1 10 Feb 2007, 11:40
3 Of a group of people, 10 play piano, 11 play guitar, 14 play getzgetzu 27 21 Apr 2006, 02:44
Display posts from previous: Sort by

In a group of 800 people, 1/5 play at least one instrument..

  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®.