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

It is currently 20 Oct 2014, 01:48

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 survey conducted to find out the readership of three Ne

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Manager
Manager
User avatar
Joined: 25 Jan 2010
Posts: 112
Location: Calicut, India
Followers: 6

Kudos [?]: 83 [2] , given: 40

In a survey conducted to find out the readership of three Ne [#permalink] New post 12 Nov 2010, 16:04
2
This post received
KUDOS
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

49% (03:13) correct 51% (03:14) wrong based on 45 sessions
In a survey conducted to find out the readership of three Newspapers A,B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40. The number of people who read newspaper B is at least 50 and at most 70. The number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C.

A. 4
B. 3
C. 2
D. 1
E. 0
[Reveal] Spoiler: OA

_________________

If u think this post is useful plz feed me with a kudo


Last edited by Bunuel on 28 Jan 2014, 00:02, edited 2 times in total.
Corrected the OA
Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 12 Nov 2010, 18:41
Expert's post
To avoid confusion, deleting this. Given a clearer explanation at the bottom.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews


Last edited by VeritasPrepKarishma on 14 Nov 2010, 18:54, edited 5 times in total.
Manager
Manager
User avatar
Joined: 25 Jan 2010
Posts: 112
Location: Calicut, India
Followers: 6

Kudos [?]: 83 [0], given: 40

Re: PS Question [#permalink] New post 12 Nov 2010, 19:15
VeritasPrepKarishma wrote:
cleetus wrote:
In a survey conducted to find out the readership of three Newspapers A,B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40. The number of people who read newspaper B is at least 50 and at most 70. The number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C.

A)4
B)3
C)2
D)1
E)0

Plz explain how. any short cut to get the answer


Make the diagram of intersection of 3 sets as given below:
Attachment:
Ques.jpg


8 people read all 3 newspapers.
85 people read at least 2 so 85 - 8 = 77 read exactly 2 newspapers (the area marked by the three x)

We have to minimize those who read A and B but not C. So we have to minimize the area with 'X' (capital x).
All three x's add up to 77. To minimize the one with 'X', try and maximize the other two regions which have 'x' (small x).
Is it possible to distribute 77 between these two regions with small x? Yes, because A is at most 40 and B is at most 70. So the two small x's can be at most 32 and 62 respectively. Therefore X can easily be 0.
Answer (E).

Note: I haven't seen intersection of 3 sets on GMAT yet (just 2 sets). Though, it is a good idea to be comfortable with the basics of how to work with three sets too.


Thanks Karishma. Thanks for the technique.
Why do we have to take maximum value for A and B.

If we give maximum values of 32 and 62 to small x regions, the value of C will be 32+64+8 = 104. According to the question, C's maximum value is 83.
_________________

If u think this post is useful plz feed me with a kudo

Manager
Manager
avatar
Joined: 10 Sep 2010
Posts: 133
Followers: 2

Kudos [?]: 12 [0], given: 7

Re: PS Question [#permalink] New post 12 Nov 2010, 19:29
Thanks Karishma. I could not solve it myself.

It is interesting that you said that you haven't seen intersection of 3 sets on GMAT yet. However, MGMAT, Knewton and other test have them.
Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 13 Nov 2010, 04:38
Expert's post
cleetus wrote:
Why do we have to take maximum value for A and B.

If we give maximum values of 32 and 62 to small x regions, the value of C will be 32+64+8 = 104. According to the question, C's maximum value is 83.


Hey cleetus,
We are not actually giving them the maximum value. The Value of X + x + x = 77.
I want to see "Can x + x be 77 so that X is minimum, that is 0?"

But, I did overlook the fact that they have given the maximum value for C as well. Let me update the solution in that light.. and thanks for pointing it out...
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews


Last edited by VeritasPrepKarishma on 14 Nov 2010, 18:54, edited 1 time in total.
Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [1] , given: 165

Re: PS Question [#permalink] New post 13 Nov 2010, 05:18
1
This post received
KUDOS
Expert's post
In fact, knowing the maximum value of C gives us a much easier solution. Since C can be at most 83 and people who read 2 or more newspapers are 85, at least 2 people will need to read A and B but not C. Look at the diagram above to see why that is so...
(Make sure you check to see that all conditions are satisfied)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
User avatar
Joined: 25 Jan 2010
Posts: 112
Location: Calicut, India
Followers: 6

Kudos [?]: 83 [0], given: 40

Re: PS Question [#permalink] New post 13 Nov 2010, 10:38
Got it.
x + x = 75. then C is having 75 + 8 = 83. Condition satisfied.
Then X = 85 - 75 - 8 = 2 rite.

Thanks Karishma
_________________

If u think this post is useful plz feed me with a kudo

Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 13 Nov 2010, 12:15
Expert's post
Fijisurf wrote:
Thanks Karishma. I could not solve it myself.

It is interesting that you said that you haven't seen intersection of 3 sets on GMAT yet. However, MGMAT, Knewton and other test have them.


Yes because it is not a bad idea to know the concept. How to draw the circles. What the intersection means etc. And anyway, if you are very comfortable with 3 sets, 2 should be cakewalk! :)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
User avatar
Status: Planning to retake.
Affiliations: Alpha Psi Omega
Joined: 25 Oct 2010
Posts: 90
Concentration: General Management, Entrepreneurship
GMAT 1: 650 Q42 V37
GRE 1: 1310 Q630 V680
GPA: 3.16
Followers: 1

Kudos [?]: 15 [0], given: 14

Re: PS Question [#permalink] New post 13 Nov 2010, 12:21
I set it up as follows:

8 = ABC
20-40 = A
50-70 = B
70-83 = C
8 = ABC
85= AB, AC, or BC

"Find the minimum number of people who read both A and B but not C."

A+B at the least is 70. Since C at the least is also 70, the minimum difference is 0.

E. +1
_________________

Did I help you? Please give me kudos.

Each moment of time ought to be put to proper use, either in business, in improving the mind, in the innocent and necessary relaxations and entertainments of life, or in the care of the moral and religious part of our nature.

-William Andrus Alcott

Senior Manager
Senior Manager
User avatar
Joined: 08 Nov 2010
Posts: 422
WE 1: Business Development
Followers: 7

Kudos [?]: 35 [0], given: 161

GMAT ToolKit User
Re: PS Question [#permalink] New post 14 Nov 2010, 08:34
Hey, I would be happy to know if my way is just lucky or its another option to solve it:

i looked only on the minimum bc we have to find the min of group AB.

I took out 8 ppl that read ABC so the new min is :
a - 12
b - 42
c - 62

Than - we know we have 85 ppl that read at least 2:
i took the min of bc and placed there all the 85 ppl that read minimum of 2 newspapers.

means - the minimum of group ab can b = 0 because we placed all the 8 of abc and the 85 ppl that read the minimum of two newspapers.

thanks.
_________________

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Expert Post
2 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [2] , given: 165

Re: PS Question [#permalink] New post 14 Nov 2010, 18:47
2
This post received
KUDOS
Expert's post
This is the data given in the question:
Attachment:
Ques1.jpg
Ques1.jpg [ 22.19 KiB | Viewed 1170 times ]


The entire shaded area is given to be 85.
So x + y + z + 8 = 85 (people who read at least 2 newspapers)
or x + y + z = 77 (people who read exactly two newspapers)

The question asks us to minimize the area x (common to A and B but not to C)
There are 77 people in x + y + z so to give as few people as possible to x, we should try and give as many as possible to y and z.

But y + z + 8 + r <= 83 (because C is at most 83. We have a minimum value for C as well but let's not worry about it right now.)
So y + z + r <= 75
Now, even if r = 0, y + z can be 75 at the most. Since x + y + z = 77,
x has to be at least 2.
Answer (C).

Let's check if it is possible to satisfy all our conditions:
If y = 25, z = 50 (We took one of the many possible values for y)
Then A could lie between 20 - 40, B could lie between 50 - 70 and C is 83. All conditions satisfied and we got the minimum value of x.

@144144 - There is a maximum limit on C. I don't think you took that into account.

Second method: You may want to do it this way:
Attachment:
Ques1.jpg
Ques1.jpg [ 22.19 KiB | Viewed 1170 times ]

The entire shaded area is 85 (including the red one)
Now look at this:
Attachment:
Ques.jpg
Ques.jpg [ 24.44 KiB | Viewed 1153 times ]

In the diagram above, the entire shaded area is at most 83.
So the red shaded area has to be at least 85 - 83 = 2
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
avatar
Joined: 16 Jul 2010
Posts: 161
Followers: 3

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

Re: PS Question [#permalink] New post 21 Nov 2010, 04:24
Nice explanation! Thanks Karishma! I found this problem very difficult. I know that every problem provides opportunities to sharpen skills but are such type of problems common to GMAT (I mean, the ones having range)?
Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 21 Nov 2010, 07:49
Expert's post
Werewolf wrote:
Nice explanation! Thanks Karishma! I found this problem very difficult. I know that every problem provides opportunities to sharpen skills but are such type of problems common to GMAT (I mean, the ones having range)?


No. GMAT questions do not have ranges of values. If I am not mistaken, this question was not from GMAT specific material. Then again, GMAT is getting a little tougher by the day. Being exposed to such questions helps in understanding the concepts. But if you wish to ignore this problem, feel free to do it.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 21 Nov 2010, 19:04
Expert's post
Sarang wrote:
Is IMO wrong??


The answer here is (C). Minimum is 2.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
avatar
Joined: 16 Jul 2010
Posts: 161
Followers: 3

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

Re: PS Question [#permalink] New post 21 Nov 2010, 22:17
VeritasPrepKarishma wrote:
Werewolf wrote:
Nice explanation! Thanks Karishma! I found this problem very difficult. I know that every problem provides opportunities to sharpen skills but are such type of problems common to GMAT (I mean, the ones having range)?


No. GMAT questions do not have ranges of values. If I am not mistaken, this question was not from GMAT specific material. Then again, GMAT is getting a little tougher by the day. Being exposed to such questions helps in understanding the concepts. But if you wish to ignore this problem, feel free to do it.


Thanks Karishma! That's a relief!!
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1718
Location: United States
Concentration: Finance
GMAT 1: 710 Q48 V39
WE: Corporate Finance (Investment Banking)
Followers: 14

Kudos [?]: 189 [0], given: 288

GMAT ToolKit User
Re: PS Question [#permalink] New post 27 Jan 2014, 08:54
cleetus wrote:
In a survey conducted to find out the readership of three Newspapers A,B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40. The number of people who read newspaper B is at least 50 and at most 70. The number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C.

A)4
B)3
C)2
D)1
E)0

Plz explain how. any short cut to get the answer


Is the answer C or E, I thought it was C but the answer bar shows E.
Would someone please confirm and/or change the answer bar?

Thanks!
J :)
Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4870
Location: Pune, India
Followers: 1147

Kudos [?]: 5331 [0], given: 165

Re: PS Question [#permalink] New post 27 Jan 2014, 20:48
Expert's post
jlgdr wrote:
cleetus wrote:
In a survey conducted to find out the readership of three Newspapers A,B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40. The number of people who read newspaper B is at least 50 and at most 70. The number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C.

A)4
B)3
C)2
D)1
E)0

Plz explain how. any short cut to get the answer


Is the answer C or E, I thought it was C but the answer bar shows E.
Would someone please confirm and/or change the answer bar?

Thanks!
J :)


Answer is (C). I have updated the OA.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Expert Post
Moderator
Moderator
User avatar
Joined: 20 Dec 2013
Posts: 152
GMAT 1: 720 Q49 V40
Followers: 1

Kudos [?]: 22 [0], given: 60

GMAT ToolKit User Premium Member Reviews Badge
Re: In a survey conducted to find out the readership of three Ne [#permalink] New post 28 Jan 2014, 16:23
Expert's post
thanks for the explanation/Venn diagram Karishma, very helpful.
_________________

MY GMAT BLOG - ADVICE - OPINIONS - ANALYSIS

Intern
Intern
avatar
Joined: 05 Feb 2013
Posts: 1
Followers: 0

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

Re: In a survey conducted to find out the readership of three Ne [#permalink] New post 02 Feb 2014, 06:26
cleetus wrote:
In a survey conducted to find out the readership of three Newspapers A,B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40. The number of people who read newspaper B is at least 50 and at most 70. The number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C.

A. 4
B. 3
C. 2
D. 1
E. 0


My method is quite simple.
Let's translate the question as follows:
A: 20-40
B: 50-70
C: 70-83
At least two: 85
All: 8

The number of people who read only two of the three newspapers: AB+AC+BC = 85-8 = 77 ---- (1)

The maximum number of people who read BC and AC: AC+BC = 83-8 = 75 ---- (2)
(Assuming the maximum value of C equally assumes the minimum value of AB.)

(1)-(2) AB = 2

The answer is "C".
Re: In a survey conducted to find out the readership of three Ne   [#permalink] 02 Feb 2014, 06:26
    Similar topics Author Replies Last post
Similar
Topics:
16 Experts publish their posts in the topic A survey was conducted to find out how many people in a hous jamifahad 19 19 Sep 2011, 09:00
2 Experts publish their posts in the topic findings of a survey anilnandyala 5 14 Nov 2010, 00:30
A manufacturer conducted a survey to determine how many rishi2377 1 02 Nov 2007, 08:25
A manufacturer conducted a survey to determine how many apollo168 8 13 Aug 2006, 03:52
An annually conducted, nationwide survey shows a continuing remgeo 13 06 Apr 2006, 06:00
Display posts from previous: Sort by

In a survey conducted to find out the readership of three Ne

  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®.