Author 
Message 
TAGS:

Hide Tags

Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1243
Concentration: Strategy, General Management

In a group of 80 college students, how many own a car? [#permalink]
Show Tags
Updated on: 03 Oct 2017, 02:31
Question Stats:
25% (01:31) correct 75% (01:29) wrong based on 1432 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.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
[ From 470 to 680My Story ] [ My Last Month Before Test ] [ GMAT Prep Analysis Tool ] [ US. Business School Dashboard ] [ Int. Business School Dashboard ]
I Can, I Will
GMAT Club Premium Membership  big benefits and savings
Originally posted by Hussain15 on 30 May 2010, 05:03.
Last edited by Bunuel on 03 Oct 2017, 02:31, edited 2 times in total.
OA added.



Current Student
Affiliations: ?
Joined: 20 Jul 2009
Posts: 186
Location: Africa/Europe
Schools: Kellogg; Ross ($$); Tuck

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
30 May 2010, 05:45
Ans should be E, We do not have enough info to respond. Consider the following chart: Attachment:
sets.png [ 4 KiB  Viewed 19544 times ]
The question is asking for the value of X. We do not have sufficient info to go forward.



Math Expert
Joined: 02 Sep 2009
Posts: 46142

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
30 May 2010, 06:34
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. Answer: B.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
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? Extrahard Quant Tests with Brilliant Analytics



Current Student
Affiliations: ?
Joined: 20 Jul 2009
Posts: 186
Location: Africa/Europe
Schools: Kellogg; Ross ($$); Tuck

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
30 May 2010, 07:47
My bad ! Well done Bunuel (as always); Hussain15 were is this question from? it seems easy at first sight but is really tricky....



Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1243
Concentration: Strategy, General Management

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
30 May 2010, 09:27



CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2657
Location: Malaysia
Concentration: Technology, Entrepreneurship
GMAT 1: 670 Q49 V31 GMAT 2: 710 Q50 V35

Re: In a group of 80 college students, how many own a car? [#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
Support GMAT Club by putting a GMAT Club badge on your blog/Facebook
GMAT Club Premium Membership  big benefits and savings
Gmat test review : http://gmatclub.com/forum/670to710alongjourneywithoutdestinationstillhappy141642.html



Manager
Joined: 06 Aug 2010
Posts: 192
Location: Boston

Re: In a group of 80 college students, how many own a car? [#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. Answer: B. Wow, nice. I thought it was C.



Senior Manager
Status: GMAT Time...!!!
Joined: 03 Apr 2010
Posts: 280
Schools: Chicago,Tuck,Oxford,cambridge

Re: In a group of 80 college students, how many own a car? [#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. Answer: B. good strategy Bunuel!!Thanx



VP
Status: Current Student
Joined: 24 Aug 2010
Posts: 1341
Location: United States
WE: Sales (Consumer Products)

Re: In a group of 80 college students, how many own a car? [#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



Manager
Joined: 07 Aug 2010
Posts: 68

Re: In a group of 80 college students, how many own a car? [#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



Manager
Joined: 19 Oct 2011
Posts: 76

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
30 Oct 2011, 10:13
I should agree that it is a great question!



Manager
Status: livin on a prayer!!
Joined: 12 May 2011
Posts: 113
Location: Australia

Re: In a group of 80 college students, how many own a car? [#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



Manager
Joined: 27 May 2008
Posts: 107

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
31 Oct 2011, 13:35
Bunuel, Nice explanation.



Manager
Joined: 12 Oct 2011
Posts: 225

Re: In a group of 80 college students, how many own a car? [#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.



Math Expert
Joined: 02 Sep 2009
Posts: 46142

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
31 Dec 2012, 03:10



Intern
Joined: 21 Mar 2009
Posts: 19

Re: In a group of 80 college students, how many own a car? [#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 2D 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 unnecessay tricks employed in any GMAT questions. Probably filtering mechanism through experimental question will always leads to nonconsistent percentile.



Director
Joined: 17 Dec 2012
Posts: 635
Location: India

Re: In a group of 80 college students, how many own a car? [#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. Answer: B. 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/bestonlinegrepreparation.php
Improve Intuition and Your Score Systematic Approaches



Manager
Joined: 13 Oct 2012
Posts: 61
Concentration: General Management, Leadership

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
03 Jan 2013, 22:25
very good ques had me stumped



Math Expert
Joined: 02 Sep 2009
Posts: 46142

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
11 Jun 2013, 07:28



Manager
Joined: 22 Feb 2009
Posts: 195

Re: In a group of 80 college students, how many own a car? [#permalink]
Show Tags
01 Aug 2014, 03:35
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. Answer: B. This is tricky. Thanks for the explanation.
_________________
......................................................................... +1 Kudos please, if you like my post




Re: In a group of 80 college students, how many own a car?
[#permalink]
01 Aug 2014, 03:35



Go to page
1 2
Next
[ 26 posts ]



