A research study found that, of 500 people surveyed, 220 : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 22 Jan 2017, 12:02

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A research study found that, of 500 people surveyed, 220

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Manager
Joined: 28 May 2009
Posts: 155
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
Followers: 8

Kudos [?]: 198 [0], given: 91

A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

06 Mar 2013, 18:37
2
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

70% (02:14) correct 30% (01:08) wrong based on 136 sessions

### HideShow timer Statistics

A research study found that, of 500 people surveyed, 220 watched neither Network A nor Network B, 120 watched only Network A, and for every person who watched both networks, 3 watched only Network B. How many of the 500 people surveyed watched both networks?

(A) 40
(B) 60
(C) 80
(D) 100
(E) 120

I always screw up with the correct usage of this relationship: [Total = Group1 + Group2 - Both + Neither] vs [Total = Group1 + Group2 + Both + Neither], i.e. when to subtract Both and when to add Both
[Reveal] Spoiler: OA

_________________
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7125
Location: Pune, India
Followers: 2138

Kudos [?]: 13694 [2] , given: 222

Re: A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

06 Mar 2013, 20:51
2
KUDOS
Expert's post
1
This post was
BOOKMARKED
Here are the two formulas

1. [Total = Group1 + Group2 - Both + Neither]

Used when Group1 includes Both.
e.g. given 160 people watch network A. This means 160 watch network A and it includes those people who watch both the networks. Similarly, Group2 includes people who watch both the networks e.g. given 160 watch network B - 160 includes the number of people who watch both networks.
Since no of people who watch both networks is included twice, you subtract it out once.

500 = 160 + 160 - 40 + 220

2. [Total = Group1 + Group2 + Both + Neither]

Used when Group1 is the number of people who watch ONLY network A
e.g. given 120 people watch ONLY network A (compare this with above where the word ONLY is missing). Group2 includes people who watch ONLY network B. Since you haven't accounted for the people who watch both, you add Both once.

500 = 120 + 120 + 40 + 220

Hope both the formulas make sense now.

Here, you are given that 120 watched only network A so you use the second formula. Also, it might be a good idea to get comfortable with venn diagrams. Such confusions do not occur if you always use the venn diagram.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews VP Status: Top MBA Admissions Consultant Joined: 24 Jul 2011 Posts: 1126 GMAT 1: 780 Q51 V48 GRE 1: 1540 Q800 V740 Followers: 124 Kudos [?]: 541 [1] , given: 19 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 06 Mar 2013, 19:53 1 This post received KUDOS 1 This post was BOOKMARKED megafan, see the attached figure. the portion in green corresponds to neither A nor B. The one in brown corresponds to only A. The one in blue to only B. The one in red to both A and B. n(Total) = n(Neither A nor B) + n(only A) + n(only B) + n(both A and B) => 500 = 220 + 120 + 3x + x => x = 160/4 = 40 Therefore 40 people watched both networks. Option A. Attachments figure.jpg [ 28.56 KiB | Viewed 2223 times ] _________________ GyanOne | Top MBA Rankings and MBA Admissions Blog Top MBA Admissions Consulting | Top MiM Admissions Consulting Premium MBA Essay Review|Best MBA Interview Preparation|Exclusive GMAT coaching Get a FREE Detailed MBA Profile Evaluation | Call us now +91 98998 31738 Math Expert Joined: 02 Sep 2009 Posts: 36598 Followers: 7096 Kudos [?]: 93460 [1] , given: 10563 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 07 Mar 2013, 00:52 1 This post received KUDOS Expert's post megafan wrote: A research study found that, of 500 people surveyed, 220 watched neither Network A nor Network B, 120 watched only Network A, and for every person who watched both networks, 3 watched only Network B. How many of the 500 people surveyed watched both networks? (A) 40 (B) 60 (C) 80 (D) 100 (E) 120 I always screw up with the correct usage of this relationship: [Total = Group1 + Group2 - Both + Neither] vs [Total = Group1 + Group2 + Both + Neither], i.e. when to subtract Both and when to add Both This might help: advanced-overlapping-sets-problems-144260.html (ADVANCED OVERLAPPING SETS PROBLEMS) _________________ Math Expert Joined: 02 Sep 2009 Posts: 36598 Followers: 7096 Kudos [?]: 93460 [1] , given: 10563 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 29 May 2013, 14:09 1 This post received KUDOS Expert's post piyushdiyora wrote: Can anyone solve the same problem using 2 way matrix A research study found that, of 500 people surveyed, 220 watched neither Network A nor Network B, 120 watched only Network A, and for every person who watched both networks, 3 watched only Network B. How many of the 500 people surveyed watched both networks? (A) 40 (B) 60 (C) 80 (D) 100 (E) 120 Attachment: Matrix.png [ 5.36 KiB | Viewed 1672 times ] From above 4x+340=500 --> x=40. Answer: A. Hope it helps. _________________ Manager Joined: 28 May 2009 Posts: 155 Location: United States Concentration: Strategy, General Management GMAT Date: 03-22-2013 GPA: 3.57 WE: Information Technology (Consulting) Followers: 8 Kudos [?]: 198 [0], given: 91 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 07 Mar 2013, 08:08 VeritasPrepKarishma wrote: Here are the two formulas 1. [Total = Group1 + Group2 - Both + Neither] Used when Group1 includes Both. e.g. given 160 people watch network A. This means 160 watch network A and it includes those people who watch both the networks. Similarly, Group2 includes people who watch both the networks e.g. given 160 watch network B - 160 includes the number of people who watch both networks. Since no of people who watch both networks is included twice, you subtract it out once. 500 = 160 + 160 - 40 + 220 2. [Total = Group1 + Group2 + Both + Neither] Used when Group1 is the number of people who watch ONLY network A e.g. given 120 people watch ONLY network A (compare this with above where the word ONLY is missing). Group2 includes people who watch ONLY network B. Since you haven't accounted for the people who watch both, you add Both once. 500 = 120 + 120 + 40 + 220 Hope both the formulas make sense now. Here, you are given that 120 watched only network A so you use the second formula. Also, it might be a good idea to get comfortable with venn diagrams. Such confusions do not occur if you always use the venn diagram. Wow, thanks a lot! This makes the problem seem like a 300-level question. I think I usually don't pay attention to the elements in the set -- i.e. whether there is an overlap or not. Note to self: watch out for only. _________________ Intern Joined: 28 Nov 2012 Posts: 48 Followers: 0 Kudos [?]: 32 [0], given: 3 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 08 Mar 2013, 14:38 and for every person who watched both networks, 3 watched only Network B. How many of the 500 people surveyed watched both networks? Can someone clarify this wording? I understood what they were testing but I couldn't figure out what that meant.... Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 7125 Location: Pune, India Followers: 2138 Kudos [?]: 13694 [0], given: 222 Re: A research study found that, of 500 people surveyed, 220 [#permalink] ### Show Tags 08 Mar 2013, 23:32 skiingforthewknds wrote: and for every person who watched both networks, 3 watched only Network B. How many of the 500 people surveyed watched both networks? Can someone clarify this wording? I understood what they were testing but I couldn't figure out what that meant.... It just gives you the relation between the two groups: - No of people who watched both networks - No of people who watched only network B It means that if there is only 1 person who watches both networks, there are 3 who watch only network B. If there are 2 people who watch both networks, there are 6 who watch only network B and so on... It is just another way of telling that the ratio of no of people watching both networks and no of people who watch only network B is 1:3 So if x people watch both networks, 3x watch only network B. _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199

Veritas Prep Reviews

Intern
Joined: 16 Dec 2012
Posts: 1
Followers: 0

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

Re: A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

29 May 2013, 09:34
Can anyone solve the same problem using 2 way matrix
Intern
Joined: 02 May 2013
Posts: 26
Concentration: International Business, Technology
WE: Engineering (Aerospace and Defense)
Followers: 1

Kudos [?]: 40 [0], given: 16

Re: A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

29 May 2013, 17:57
let x = only A =120 given
y = both A and B
z=only B
w= neither A and B = 220 given
also given z=3*y

from below picture
x+y+z+w = 500
using above given values
y+z =160

and 4*y = 160(since z=3*y)
y=40

Sol:A
Attachments

venn_1.JPG [ 7.66 KiB | Viewed 1625 times ]

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13501
Followers: 577

Kudos [?]: 163 [0], given: 0

Re: A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

19 Jun 2014, 07:07
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1858
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 47

Kudos [?]: 1937 [0], given: 193

Re: A research study found that, of 500 people surveyed, 220 [#permalink]

### Show Tags

25 Jul 2014, 01:26
Refer diagram below

We require to find the shaded region

Equation setup would be:

120 + x + 3x + 220 = 500

4x = 160

x = 40

Attachments

shad.png [ 4.15 KiB | Viewed 1026 times ]

_________________

Kindly press "+1 Kudos" to appreciate

Re: A research study found that, of 500 people surveyed, 220   [#permalink] 25 Jul 2014, 01:26
Similar topics Replies Last post
Similar
Topics:
In a survey it was found that 75% of those surveyed liked mustard and 1 19 Dec 2016, 04:34
In a survey it was found that 84% of those surveyed liked mustard and 1 13 Dec 2016, 06:03
3 A survey of n people in the town of Eros found that 50%... 3 08 Jul 2016, 02:13
2 Tom found a box of 220 baseball cards. Being a thoughtful older brothe 6 11 Apr 2016, 03:06
12 Of the 500 business people surveyed, 78 percent said that 6 01 Dec 2012, 01:11
Display posts from previous: Sort by

# A research study found that, of 500 people surveyed, 220

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.