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 350,000 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:

Re: DS: x multiple of y? [#permalink]
04 May 2008, 19:55

chineseburned wrote:

If x and y are both integers greater than 1, is x a multiple of y?

(1) 3y^2 + 7y = x (2) x^2 -x is a multiple of y

A.

Given: x > 1 y > 1 n, x, y = integer Asking: Is x = ny?

(1) x = y*(3y + 7) Because y is integer, (3y + 7) must be integer; therefore, x must equal integer * y SUFFICIENT

(2) x^2 - x = ny Plug in numbers to satisfy above condition... Say x=3, n=1, then y=6. In this case, x is not a multiple of y. Say x=6, n=15, then y=2. In this case, x is a multiple of y. The solution actually depends on what n is, and the only condition we have is n is integer. Therefore, it is INSUFFICIENT

Re: DS: x multiple of y? [#permalink]
17 Jul 2010, 07:12

1

This post received KUDOS

Expert's post

dauntingmcgee wrote:

So from x(x-1)=yk, can we not derive:

x=y*k/(x-1)=yk?

In which case the answer is C, not A.

We don't know whether \frac{k}{x-1} is an integer, hence we can not write x=yn (where n is an integer) from x(x-1)=yk.

If x and y are integers great than 1, is x a multiple of y?

Is x=ny, where n=integer\geq{1}?

(1) 3y^2+7y=x --> y(3y+7)=x --> as 3y+7=integer, then y*integer=x --> x is a multiple of y. Sufficient.

(2) x^2-x is a multiple of y --> x^2-x=my --> x(x-1)=my --> x can be multiple of y (x=2 and y=2) OR x-1 can be multiple of y (x=3 and y=2) or their product can be multiple of y (x=3 and y=6). Not sufficient.

I´ve done an interview at Accepted.com quite a while ago and if any of you are interested, here is the link . I´m through my preparation of my second...

It’s here. Internship season. The key is on searching and applying for the jobs that you feel confident working on, not doing something out of pressure. Rotman has...