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:

0% (00:00) correct
0% (00:00) wrong based on 1 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Hi,

I can't figure out this GMATPrep question that I got wrong. If someone could help, I'd greatly appreciate it. The answer was C (standard DS answer choices).

Thanks,
Marcus

In the xy-plane, does the line with equation y=3x+2 contain the point (r,s)?

In the xy-plane, does the line with equation y=3x+2 contain the point (r,s)?

(1) (3r+2-s)(4r+9-s)=0
(2) (4r-6-s)(3r+2-s)=0

From (1):
3r+2-s = 0
=> s = 3r + 2 (its on the line y=3x+2)

or 4r+9-s = 0
=> s = 4r + 9 (its not on line y=3x+2)

Hence not sufficient.

From (2):
s = 4r - 6 (not on the line)

or s = 3r + 2 (it is on the line)

Hence not sufficient.

If both (1) and (2) are taken into account:
3r+2-s=0 is true and hence they say the answer is C. But I'm not sure how to prove that 3r+2-s=0 is true and not the other 2 equations ... if someone can show that then it would be great.

4r + 9 - s = 0 AND 4r - 6 - s = 0 OR 3r + 2 - s = 0

(reason is obvious, but let me know if it has to be explained)

Please explain this.

Well if the product or 2 numbers is 0 the number1 = 0 OR number2 =0, right ?
Here we have
XY = 0 AND
XZ = 0 if we take Y = 4r + 9 -s and Z = 4r - 6 - s and 3r + 2 - s)

Since X is common in both equations then either X = 0 i.e both expressions become 0 OR X != 0 and Y = 0 as well as Z = 0 for both expressions to be zero. The third case is X, Y, Z are all 0 which is a subset of Y = 0 and Z = 0.