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:

if X and Y are integers greater than 1, is X a multiple of Y ?

(1) 3y² +7y = x (2) X²- X is a a multiple of Y

i came up with something like this:

statement :1

y=3; 27+21=84 y=2; 12+14=26 so they are multiple

but i cannot

figure out B can anyone explain it clearly

2 means that X(X-1) is multiple of Y. In the product X(X-1), there are two case (even three case) a. X is multiple of Y, but X-1 is not b. X-1 is multiple of Y, but X is not c. must be X(X-1) just enough to be multiple of Y

Re: DS from Gmat Prep - multiple of y [#permalink]

Show Tags

28 Jan 2009, 19:48

ongste wrote:

Hi,

I am not sure whether this question has been asked here before,..

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

i) 3y^2 + 7y = x ii) x^2 - x is a multiple of y

thanks

i) 3y^2 + 7y = x y (3y + 7) = x since y is an integer, (3y + 7) is also an integer. x is (3y + 7) times of y. suff.

ii) x^2 - x = yk x (x - 1) = yk

Not suff cuz we do not know whether k is an integer. however x, y and (x-1) all are integers, by k = ? do not know. lets say x = 5, x-1 = 4 and y = 3. k = 20/3. no x = 5, x-1 = 4 and y = 10. k = 2. yes.

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

1) 3y^2 + 7y = x

2) x^2 - x is a multiple of y

The answer is A.

Using 1 we get x = 3y^2 + 7y x =y(3y+7)

So clearly from above x is a multiple of y. So 1 is sufficient.

Using 2 we get x^2 -x = y y = x(x-1).

So from above we get y is multiple of x and x-1. So x will be a multiple of y in case both x =y=2 we get 2 = 2*(2-1). However not true for other values of x, so 2 is insufficient.

Version 8.1 of the WordPress for Android app is now available, with some great enhancements to publishing: background media uploading. Adding images to a post or page? Now...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...