It is currently 24 Sep 2017, 18:04

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

In a group of 80 college students, how many own a car? (1)

Author Message
TAGS:

Hide Tags

Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1295

Kudos [?]: 1199 [19], given: 157

Concentration: Strategy, General Management
GMAT 1: 680 Q48 V34
In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

30 May 2010, 05:03
19
KUDOS
53
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

24% (01:30) correct 76% (01:28) wrong based on 1596 sessions

HideShow timer Statistics

In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.
(2) Of the students who own a car, 42% are female.
[Reveal] Spoiler: OA

_________________

Last edited by Bunuel on 11 Jun 2013, 07:19, edited 1 time in total.

Kudos [?]: 1199 [19], given: 157

Math Expert
Joined: 02 Sep 2009
Posts: 41699

Kudos [?]: 124810 [54], given: 12079

In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

30 May 2010, 06:34
54
KUDOS
Expert's post
19
This post was
BOOKMARKED
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male. Clearly insufficient.

(2) Of the students who own a car, 42% are female --> let # of students who own a car be $$x$$ --> $$0.42x=$$ # of females who own a car. But $$0.42x$$ must be an integer, as it represent # of females. $$0.42x=integer$$ --> $$\frac{21}{50}x=integer$$ --> $$x$$ is a multiple of 50: 50, 100, 150, ... But $$x$$ (# of students who own car) must also be less than (or equal to) 80. So $$x=50$$. sufficient.

_________________

Kudos [?]: 124810 [54], given: 12079

Manager
Joined: 22 Feb 2009
Posts: 215

Kudos [?]: 170 [3], given: 148

Re: In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

01 Aug 2014, 03:35
3
KUDOS
5
This post was
BOOKMARKED
Bunuel wrote:
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male. Clearly insufficient.

(2) Of the students who own a car, 42% are female --> let # of students who own a car be $$x$$ --> $$0.42x=$$ # of females who own a car. But $$0.42x$$ must be an integer, as it represent # of females. $$0.42x=integer$$ --> $$\frac{21}{50}x=integer$$ --> $$x$$ is a multiple of 50: 50, 100, 150, ... But $$x$$ (# of students who own car) must also be less than (or equal to) 80. So $$x=50$$. sufficient.

This is tricky. Thanks for the explanation.
_________________

.........................................................................
+1 Kudos please, if you like my post

Kudos [?]: 170 [3], given: 148

Current Student
Affiliations: ?
Joined: 20 Jul 2009
Posts: 191

Kudos [?]: 38 [1], given: 6

Location: Africa/Europe
Schools: Kellogg; Ross ($$); Tuck Re: Good Overlapping Set Problem [#permalink] Show Tags 30 May 2010, 05:45 1 This post received KUDOS 1 This post was BOOKMARKED Ans should be E, We do not have enough info to respond. Consider the following chart: Attachment: sets.png [ 4 KiB | Viewed 17730 times ] The question is asking for the value of X. We do not have sufficient info to go forward. Kudos [?]: 38 [1], given: 6 Retired Moderator Status: The last round Joined: 18 Jun 2009 Posts: 1295 Kudos [?]: 1199 [1], given: 157 Concentration: Strategy, General Management GMAT 1: 680 Q48 V34 Re: Good Overlapping Set Problem [#permalink] Show Tags 30 May 2010, 06:59 1 This post received KUDOS Excellent!!! OA is "B". _________________ Kudos [?]: 1199 [1], given: 157 Current Student Affiliations: ? Joined: 20 Jul 2009 Posts: 191 Kudos [?]: 38 [0], given: 6 Location: Africa/Europe Schools: Kellogg; Ross ($$); Tuck
Re: Good Overlapping Set Problem [#permalink]

Show Tags

30 May 2010, 07:47
Well done Bunuel (as always); Hussain15 were is this question from? it seems easy at first sight but is really tricky....

Kudos [?]: 38 [0], given: 6

Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1295

Kudos [?]: 1199 [0], given: 157

Concentration: Strategy, General Management
GMAT 1: 680 Q48 V34
Re: Good Overlapping Set Problem [#permalink]

Show Tags

30 May 2010, 09:27
The question is from Magoosh Quant Bank. The bank is a good source of quality GMAT questions.

Posted from my mobile device
_________________

Kudos [?]: 1199 [0], given: 157

CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2764

Kudos [?]: 1856 [0], given: 235

Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Re: Good Overlapping Set Problem [#permalink]

Show Tags

14 Sep 2010, 00:17
wow !!

Great question.
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned

Jo Bole So Nihaal , Sat Shri Akaal

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Kudos [?]: 1856 [0], given: 235

Manager
Joined: 06 Aug 2010
Posts: 219

Kudos [?]: 222 [0], given: 5

Location: Boston
Re: Good Overlapping Set Problem [#permalink]

Show Tags

14 Sep 2010, 07:39
Bunuel wrote:
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

(1) Of the students who do not own a car, 14 are male. Clearly insufficient.

(2) Of the students who own a car, 42% are female --> let # of students who own a car be $$x$$ --> $$0.42x=$$ # of females who own a car. But $$0.42x$$ must be an integer, as it represent # of females. $$0.42x=integer$$ --> $$\frac{21}{50}x=integer$$ --> $$x$$ is a multiple of 50: 50, 100, 150, ... But $$x$$ (# of students who own car) must also be less than (or equal to) 80. So $$x=50$$. sufficient.

Wow, nice. I thought it was C.

Kudos [?]: 222 [0], given: 5

Senior Manager
Status: GMAT Time...!!!
Joined: 03 Apr 2010
Posts: 293

Kudos [?]: 56 [0], given: 7

Schools: Chicago,Tuck,Oxford,cambridge
Re: Good Overlapping Set Problem [#permalink]

Show Tags

16 Sep 2010, 11:33
Bunuel wrote:
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

(1) Of the students who do not own a car, 14 are male. Clearly insufficient.

(2) Of the students who own a car, 42% are female --> let # of students who own a car be $$x$$ --> $$0.42x=$$ # of females who own a car. But $$0.42x$$ must be an integer, as it represent # of females. $$0.42x=integer$$ --> $$\frac{21}{50}x=integer$$ --> $$x$$ is a multiple of 50: 50, 100, 150, ... But $$x$$ (# of students who own car) must also be less than (or equal to) 80. So $$x=50$$. sufficient.

good strategy Bunuel!!Thanx

Kudos [?]: 56 [0], given: 7

VP
Status: Current Student
Joined: 24 Aug 2010
Posts: 1345

Kudos [?]: 423 [0], given: 73

Location: United States
GMAT 1: 710 Q48 V40
WE: Sales (Consumer Products)
Re: Good Overlapping Set Problem [#permalink]

Show Tags

16 Sep 2010, 17:33
Awesome question. I too thought the answer is E. That's why it's a good idea to set up equations because these things become plain as day when you write them out. Important to remember that all statements are true.
_________________

The Brain Dump - From Low GPA to Top MBA (Updated September 1, 2013) - A Few of My Favorite Things--> http://cheetarah1980.blogspot.com

Kudos [?]: 423 [0], given: 73

Manager
Joined: 07 Aug 2010
Posts: 76

Kudos [?]: 19 [0], given: 9

Re: Good Overlapping Set Problem [#permalink]

Show Tags

10 Oct 2010, 22:51
good q. thanks to bunuel for the explanation.
_________________

Click that thing - Give kudos if u like this

Kudos [?]: 19 [0], given: 9

Manager
Joined: 19 Oct 2011
Posts: 84

Kudos [?]: 94 [0], given: 1

Re: Good Overlapping Set Problem [#permalink]

Show Tags

30 Oct 2011, 10:13
I should agree that it is a great question!

Kudos [?]: 94 [0], given: 1

Manager
Status: livin on a prayer!!
Joined: 12 May 2011
Posts: 120

Kudos [?]: 34 [0], given: 1

Location: Australia
Re: Good Overlapping Set Problem [#permalink]

Show Tags

31 Oct 2011, 09:45
Bunuel,

Amazing solution!
_________________

Aim for the sky! (800 in this case)
If you like my post, please give me Kudos

Kudos [?]: 34 [0], given: 1

Manager
Joined: 27 May 2008
Posts: 126

Kudos [?]: 76 [0], given: 4

Re: Good Overlapping Set Problem [#permalink]

Show Tags

31 Oct 2011, 13:35
Bunuel, Nice explanation.

Kudos [?]: 76 [0], given: 4

Senior Manager
Joined: 12 Oct 2011
Posts: 257

Kudos [?]: 59 [0], given: 110

Re: In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

16 Dec 2011, 11:48
Yep. Clicked on E. Wrong answer.
B is the right answer. I wonder why I miss out on such minor details.

Kudos [?]: 59 [0], given: 110

Math Expert
Joined: 02 Sep 2009
Posts: 41699

Kudos [?]: 124810 [0], given: 12079

Re: In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

31 Dec 2012, 03:10
gmatfighter12 wrote:
How can i detect this trap on the real test?

Practice. Check similar questions here: devil-s-dozen-129312.html#p1063867
_________________

Kudos [?]: 124810 [0], given: 12079

Intern
Joined: 21 Mar 2009
Posts: 20

Kudos [?]: 24 [0], given: 0

Re: In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

31 Dec 2012, 07:51
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

I am confident this question will never be tested in GMAT. There are two parts of my argument. First GMAT does tests 2-D table in a variety of ways. It also tests the two variable one equation where answers can be deduced sometime based on the constraints used, for example a 21c pencil and 23c pen bought for some amount may have only one solution as it has only one such possible combination etc. That leads me to thing why the creator here has combined the two and probably a tried a super trick question. But GMAT is not about such tricks. GMAT tests practical scenario, for example, two variable one equation leading to a unique solution is a well known optimazation problem and there are tons of those tested in high school algebra and in real world.

Second, I have never seen this sort of un-necessay tricks employed in any GMAT questions. Probably filtering mechanism through experimental question will always leads to non-consistent percentile.

Kudos [?]: 24 [0], given: 0

Director
Joined: 17 Dec 2012
Posts: 601

Kudos [?]: 509 [0], given: 16

Location: India
Re: Good Overlapping Set Problem [#permalink]

Show Tags

01 Jan 2013, 01:53
Bunuel wrote:
Hussain15 wrote:
In a group of 80 college students, how many own a car?

(1) Of the students who do not own a car, 14 are male.

(2) Of the students who own a car, 42% are female.

(1) Of the students who do not own a car, 14 are male. Clearly insufficient.

(2) Of the students who own a car, 42% are female --> let # of students who own a car be $$x$$ --> $$0.42x=$$ # of females who own a car. But $$0.42x$$ must be an integer, as it represent # of females. $$0.42x=integer$$ --> $$\frac{21}{50}x=integer$$ --> $$x$$ is a multiple of 50: 50, 100, 150, ... But $$x$$ (# of students who own car) must also be less than (or equal to) 80. So $$x=50$$. sufficient.

I think since the answer is based on a fine point, that the number pf car owners has to be an integer, they need to have covered that angle well. But I think they did not. The integer mentioned above can be 0 and need not be positive. I am pointing this out because in a quantitative test, precision is important.
_________________

Srinivasan Vaidyaraman
Sravna
http://www.sravnatestprep.com/regularcourse.php

Free Online Coaching
Standardized Approaches

Kudos [?]: 509 [0], given: 16

Manager
Joined: 13 Oct 2012
Posts: 69

Kudos [?]: -9 [0], given: 0

Schools: IE '15 (A)
GMAT 1: 760 Q49 V46
Re: In a group of 80 college students, how many own a car? (1) [#permalink]

Show Tags

03 Jan 2013, 22:25
very good ques had me stumped

Kudos [?]: -9 [0], given: 0

Re: In a group of 80 college students, how many own a car? (1)   [#permalink] 03 Jan 2013, 22:25

Go to page    1   2    Next  [ 28 posts ]

Display posts from previous: Sort by