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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

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 is B...

Shouldnt the answer be E...

B is correct!!

Let a and b are the number of students who own and do not own a car resp. We need to find the value of B. Also a+b = 80 Statemen1 : not sufficient.

Statement 2: 42% of a = female => 42a/100 = female = 21a/50.

Now here is the trick !! number of females must be an integer. => a must have minimum value of 50.

if a = 50 => females = 21. a can not be 100 as total is 80

=> a has to be 50. Hence B

The value of 'a' can be zero as well, at least mathematically as that would also justify above conditions. Of course, that makes the statement 2 a tad impractical, but still correct mathematically. So, the value of 'a' can not be ascertained for sure and the answer should still be E.

A bit of an ambiguous question for sure. Maybe the questions needs to mention that a and b are non-zero or something.

It can be 0 and then 42% of the same would also be 0 (number of females). Where does it say in the question that number of females have to be non-zero. All we know is that females = 0.42*a and this equation can be valid at both a = 0 and a = 50 without contradicting anything given in the question.

It can be 0 and then 42% of the same would also be 0 (number of females). Where does it say in the question that number of females have to be non-zero. All we know is that females = 0.42*a and this equation can be valid at both a = 0 and a = 50 without contradicting anything given in the question.

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

The phrase 'Of the students who own a car' already tells you that some students own a car, so it is not a possibility that 0 students own a car. Further, if I were to tell you that 0 people own a car, and I asked you what percentage of the students who own a car are female, you would not say "42%". It would be meaningless to assign a percentage in that case. The GMAT would never tell you '42% of people own a car' and then make the 'trap' that 0 people might own a car, because most test takers would, very reasonably, assume the number of car owners needs to be non-zero.

So if you see a phrase like '1/3 of the people in North America who own a computer are Canadian' or '45% of the marbles in a bag are green', you can certainly assume that the number of North Americans who own a computer, or the number of marbles in the bag, is not zero. _________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

Re: In a group of 80 college students, how many own a car? (1) [#permalink]
29 Mar 2014, 10:31

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. _________________

Re: In a group of 80 college students, how many own a car? [#permalink]
29 Mar 2014, 10:48

Expert's post

1

This post was BOOKMARKED

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.

Low GPA MBA Acceptance Rate Analysis Many applicants worry about applying to business school if they have a low GPA. I analyzed the low GPA MBA acceptance rate at...

http://blog.davidbbaker.com/wp-content/uploads/2015/11/12249800_10153820891439090_8007573611012789132_n.jpg When you think about an MBA program, usually the last thing you think of is professional collegiate sport. (Yes American’s I’m going...