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 certain class consisting of 36 students, some boys and [#permalink]
08 Feb 2011, 03:33

3

This post received KUDOS

7

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

55% (hard)

Question Stats:

58% (02:25) correct
42% (01:36) wrong based on 343 sessions

In a certain class consisting of 36 students, some boys and some girls, exactly 1/3 of the boys and exactly 1/4 of the girls walk to school. What is the greatest possible number of students in this class who walk to school?

Re: In a certain class [#permalink]
08 Feb 2011, 06:50

1

This post received KUDOS

Expert's post

5

This post was BOOKMARKED

GMATD11 wrote:

In a certain class consisting of 36 students, some boys and some girls, exactly 1/3 of the boys and exactly 1/4 of the girls walk to school. what is the greatest possible number of students in this class who walk to school? a)9 b)10 c)11 d)12 e)13

Let # of boys be \(b\), then # of girls will be \(36-b\). We want to maximize \(\frac{b}{3}+\frac{36-b}{4}\) --> \(\frac{b}{3}+\frac{36-b}{4}=\frac{b+3*36}{12}=\frac{b}{12}+9\), so we should maximize \(b\), but also we should make sure that \(\frac{b}{12}+9\) remains an integer (as it represent # of people). Max value of \(b\) for which b/12 is an integer is for \(b=24\) (b can not be 36 as we are told that there are some # of girls among 36) --> \(\frac{b}{12}+9=2+9=11\).

Answer: C.

Or: as there are bigger percentage of boys who walk then we should maximize # of boys, but we should ensure that \(\frac{b}{3}\) and \(\frac{36-b}{4}\) are integers. So \(b\) should be max multiple of 3 for which \(36-b\) is a multiple of 4, which turns out to be for \(b=24\) --> \(\frac{b}{3}+\frac{36-b}{4}=11\).

Re: In a certain class consisting of 36 students, some boys and [#permalink]
14 Oct 2013, 22:07

GMATD11 wrote:

In a certain class consisting of 36 students, some boys and some girls, exactly 1/3 of the boys and exactly 1/4 of the girls walk to school. What is the greatest possible number of students in this class who walk to school?

A. 9 B. 10 C. 11 D. 12 E. 13

let number of boys in a class are x then number of gals become 36-x

1/3x+1/4(36-x)=9+x/12

x cannot be 36 as there are some gals in class so maximum value of x/12 can be 2

Answer C

any other method to solve this question.

Lets apply process of elimination

option A: See, 9 cannot be expressed as sum of multiple of 3 and 4. neither can 10, 12 or 13. only 11 can be expressed a sum of multiples of 3 and 4.

11= 3+ 2(4)

since we need 1/3 of boys, 1/4th of girls. and number of boys and girls have to be integers.

11 is the only option that satisfies the situation.

Re: In a certain class consisting of 36 students, some boys and [#permalink]
13 Dec 2013, 10:27

1

This post received KUDOS

Answer is C.

It can be easily solve by using a number which is multiple of 3 & 4 together and less than 36. So the number would be 12 & 24 only. Consider one of the number as count of boys or girls.

Say B=12 then G=24 which means 1/3 of 12 + 1/4 of 24=10 Now try for 24. Say B=24 then G=12 which means 1/3 of 24 + 1/4 of 12=11

So answer is C in less than a minute. +1 for me. cheers.

Re: In a certain class consisting of 36 students, some boys and [#permalink]
28 Jan 2015, 05:18

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. _________________

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...