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:

When integer r is divided by 7, the remainder is 3. When [#permalink]

Show Tags

29 Sep 2012, 12:14

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

15% (low)

Question Stats:

79% (02:01) correct
21% (00:52) wrong based on 106 sessions

HideShow timer Statistics

When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 - s is divided by 7?

Re: What is the remainder when r^2 < s is divided by 7? [#permalink]

Show Tags

29 Sep 2012, 13:50

1

This post received KUDOS

aeros232 wrote:

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 < s is divided by 7?

\(r=7a+3\) for some integer \(a\) and \(s=7b+3\) for some integer \(b.\) Then \(r^2\) is a multiple M7 + 2 (multiple of 7 plus 2), so the difference \(r^2-s\) is M7 + 2 - 3 = M7 - 1 = M7 - 7 + 6 which is M7 + 6.

Answer E.
_________________

PhD in Applied Mathematics Love GMAT Quant questions and running.

Re: What is the remainder when r^2 - s is divided by 7? [#permalink]

Show Tags

29 Sep 2012, 22:52

1

This post received KUDOS

aeros232 wrote:

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 - s is divided by 7?

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 - s is divided by 7?

i would suggest to take num rather than doing it algerabically.

take 10.. when it divided by 7 it will have remainder 3.. So R=10..

S will also B 10..

Square of 10..=100

r2-s..100-10=90..

90 /7 ..u l have remained 6 ..

Hope it helps !

That's correct. +1.

r^2 - s must yield the same reminder when divided by 7 for every r and s which satisfy the given conditions. Thus picking numbers would be the easiest way to deal with this question.
_________________

Re: What is the remainder when r^2 < s is divided by 7? [#permalink]

Show Tags

29 Sep 2012, 14:01

EvaJager wrote:

aeros232 wrote:

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 < s is divided by 7?

\(r=7a+3\) for some integer \(a\) and \(s=7b+3\) for some integer \(b.\) Then \(r^2\) is a multiple M7 + 2 (multiple of 7 plus 2), so the difference \(r^2-s\) is M7 + 2 - 3 = M7 - 1 = M7 - 7 + 6 which is M7 + 6.

Answer E.

Yes, you are right!!! And by the way, excellent explanation, thanks!!
_________________

Aeros "Why are you trying so hard to fit in when you were born to stand out?" "Do or do not. There is no 'try'..."

Re: What is the remainder when r^2 - s is divided by 7? [#permalink]

Show Tags

29 Sep 2012, 23:06

aeros232 wrote:

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 - s is divided by 7?

I was wondering if my approach is okay.. Here's my work. r/7 = 3 s/7 = 3 r^2 - s / 7 Since everything is divided by 7, you can cancel all of those out. R = S R = 3 S = 3

Re: When integer r is divided by 7, the remainder is 3. When [#permalink]

Show Tags

01 Oct 2012, 08:23

Bunuel wrote:

sanjoo wrote:

aeros232 wrote:

52. When integer r is divided by 7, the remainder is 3. When integer s is divided by 7, the remainder is 3 also. What is the remainder when r^2 - s is divided by 7?

i would suggest to take num rather than doing it algerabically.

take 10.. when it divided by 7 it will have remainder 3.. So R=10..

S will also B 10..

Square of 10..=100

r2-s..100-10=90..

90 /7 ..u l have remained 6 ..

Hope it helps !

That's correct. +1.

r^2 - s must yield the same reminder when divided by 7 for every r and s which satisfy the given conditions. Thus picking numbers would be the easiest way to deal with this question.

Thanks for kudos ..MATH GURU....
_________________

Bole So Nehal.. Sat Siri Akal.. Waheguru ji help me to get 700+ score !

Since my last post, I’ve got the interview decisions for the other two business schools I applied to: Denied by Wharton and Invited to Interview with Stanford. It all...

[rss2posts title=The MBA Manual title_url=https://mbamanual.com/2016/11/22/mba-vs-mim-guest-post/ sub_title=MBA vs. MiM :3qa61fk6]Hey, guys! We have a great guest post by Abhyank Srinet of MiM-Essay . In a quick post and an...

Marketing is one of those functions, that if done successfully, requires a little bit of everything. In other words, it is highly cross-functional and requires a lot of different...