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

It is currently 25 Oct 2014, 09:03

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

overlapping sets

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 25 Aug 2009
Posts: 4
Followers: 0

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

overlapping sets [#permalink] New post 10 Mar 2010, 04:28
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

57% (04:10) correct 43% (00:58) wrong based on 6 sessions
1) All of the students of Music High School are in the band, the orchestra, or both.80% of the students are in only one group.There are 119 students in the band.If 50% of the students are in the band only, how many students are in the orchestra only?
A)30 B)51 C)60 D)85 E)119

OA-(B)

2) Of the 645 speckled trout in a certain fishery that contains only speckled and rainbow trout, the number of males is 45 more than twice the number of females.If the ratio of females speckled trout to male rainbow trout is 4:3 and the ratio of male rainbow trout to all trout is 3:20, how many female rainbow trout are there?
A)192 B)195 C)200 D)205 E)208

OA- (D)
Senior Manager
Senior Manager
User avatar
Joined: 13 Dec 2009
Posts: 264
Followers: 10

Kudos [?]: 111 [0], given: 13

Reviews Badge
Re: overlapping sets [#permalink] New post 11 Mar 2010, 03:03
for the
indolent wrote:
1) All of the students of Music High School are in the band, the orchestra, or both.80% of the students are in only one group.There are 119 students in the band.If 50% of the students are in the band only, how many students are in the orchestra only?
A)30 B)51 C)60 D)85 E)119

OA-(B)

2) Of the 645 speckled trout in a certain fishery that contains only speckled and rainbow trout, the number of males is 45 more than twice the number of females.If the ratio of females speckled trout to male rainbow trout is 4:3 and the ratio of male rainbow trout to all trout is 3:20, how many female rainbow trout are there?
A)192 B)195 C)200 D)205 E)208

OA- (D)



First question

let's suppose X is the no of total students

so no of students who are in one group only = 0.8X
and no of students who are only band = 0.5x
so, no of students who are orchestra only = 0.8x-0.5x=0.3x

now the no of students who are in both groups = x - 0.8x = 0.2x
so, no of students who are in band = 0.5x+0.2x
=>119 = 0.5x + 0.2x
=>119 = 0.7x
=>x = 170

no of students in orchestra only = 0.3 x = 170 * 0.3 = 51

so answer is B

For the Second question, I m getting following answer

lets suppose trouts are
r(m) are male rainbow trouts and r(f) are female rainbow trouts
s(m) are male rainbow trouts and s(f) are female rainbow trouts

since, of 645 speckled trout
s(m)+s(f) = 645,

the number of males is 45 more than twice the number of females
so s(m) = 2s(f)+45 =>3s(f)+45 = 645 => S(f) = 200

means s(f) is 200 and s(m) is 445

ratio of females speckled trout to male rainbow trout is 4:3
so, s(f)/r(m) = 4/3=> 200/r(m) = 4/3=>r(m) = 150

and the ratio of male rainbow trout to all trout is 3:20
so, r(m)/alltrouts = 3/20 => 150/alltrouts = 3/20 => all trouts = 1000

now no of all trouts = s(f) + s(m) + r(m)+r(f)

1000 = 200+445+150+r(f)=>r(f) = 1000 - 795 => 205

hence no of female rainbow trouts is 205 D
_________________

My debrief: done-and-dusted-730-q49-v40

Manager
Manager
avatar
Joined: 16 May 2011
Posts: 205
Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE: Law (Law)
Followers: 1

Kudos [?]: 30 [0], given: 37

GMAT ToolKit User
Re: overlapping sets [#permalink] New post 21 May 2011, 22:38
B NOT B TOTAL

O S 0.3

NOT O S 0.5 zero

TOTAL 119 S 0.3 S


0rchestra/not band)+(band/not orchestra)=0.8 )
b/not o=0.5 therefore o/not b=0.3
not o/not b is zero

S0.7=119

S=170

0.3S=51
VP
VP
avatar
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1364
Followers: 12

Kudos [?]: 144 [0], given: 10

Re: overlapping sets [#permalink] New post 23 May 2011, 22:01
1. 0.7x = 119 gives x = 170 = total
thus 0.3x * 170 = 51

2. 445+200 = 645

200:150 = 4:3
150: 1000 = 3:20

thus 1000-645 = 355
355-150 = 205 D
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

Re: overlapping sets   [#permalink] 23 May 2011, 22:01
    Similar topics Author Replies Last post
Similar
Topics:
2 Overlapping sets dimri10 6 13 Jun 2011, 03:47
5 overlapping sets ramana 7 21 Jul 2010, 01:43
Experts publish their posts in the topic Overlapping Sets Hussain15 7 15 Jul 2010, 23:45
overlapping sets thailandvc 7 19 Sep 2009, 21:28
Overlapping Sets MatiasMM 1 11 Sep 2009, 14:25
Display posts from previous: Sort by

overlapping sets

  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®.