BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

challenge DS

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 1337
Joined: Sat Dec 27, 2008 6:29 pmFollowed by: 10 members
Thanked: 127 times
by Night reader » Tue Jan 11, 2011 12:56 am
In the xy-plane, if line m has negative slope and passes through the point (r; 6), is the x-intercept of line m positive?

(1) The slope of line m is - 1/2

(2) r > 0
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 161
Joined: Mon Apr 05, 2010 9:06 am
Location: Mumbai
Thanked: 37 times

by 4GMAT_Mumbai » Tue Jan 11, 2011 1:35 am
Hi,

Thanks for the interesting Q ...

1. The x intercept could either be -ve or +ve as it entirely depends on the value of r. If the line meets the x-axis at (a,0);

then the slope = (6-0) / (r - a) = -0.5

12 = a-r.

Whether a is +ve or not depends on r. Hence, insuff ...

2. r > 0.

then slope = (6-0) / (r - a) = some -ve number

So, r - a < 0

a > r

a > a positive r.

So, a also has to be +ve.

Answer: B ?
Naveenan Ramachandran
4GMAT, Dadar(W) & Ghatkopar(W), Mumbai
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1337
Joined: Sat Dec 27, 2008 6:29 pmFollowed by: 10 members
Thanked: 127 times

by Night reader » Tue Jan 11, 2011 2:46 am
4GMAT_Mumbai wrote:Hi,

Thanks for the interesting Q ...

1. The x intercept could either be -ve or +ve as it entirely depends on the value of r. If the line meets the x-axis at (a,0);

then the slope = (6-0) / (r - a) = -0.5

12 = a-r.

Whether a is +ve or not depends on r. Hence, insuff ...

2. r > 0.

then slope = (6-0) / (r - a) = some -ve number

So, r - a < 0

a > r

a > a positive r.

So, a also has to be +ve.

Answer: B ?
flawless reasoning and correct answer! thanks

BTW, when the e-book of 4gmat on number theory and inequalities will be available? I got one for perms, prob and combin. - awesome stuff
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pmFollowed by: 523 members
Location: Milpitas, CA
Thanked: 1854 times
GMAT Score:770

by Anurag@Gurome » Tue Jan 11, 2011 3:52 am
Night reader wrote:In the xy-plane, if line m has negative slope and passes through the point (r; 6), is the x-intercept of line m positive?

(1) The slope of line m is - 1/2
(2) r > 0
Sometimes the problems on coordinate geometry can be easily solved by drawing or visualizing the scenario. This problem is a good example to learn that. See the below figure.
Image

Statement 1: two lines are shown with negative slope (I've not shown the slope as the value of the slope doesn't matter), one of them has positive x-intercept and other one has negative.

Not sufficient

Statement 2: As r is positive, the point (r, 6) lies on the first quadrant. Any line having negative slope and passing through any point on the first quadrant must have a positive x-intercept.

Sufficient.

The correct answer is B.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 261
Joined: Wed Mar 31, 2010 8:37 pmFollowed by: 3 members
Location: Varanasi
Thanked: 11 times

by ankur.agrawal » Tue Jan 11, 2011 5:35 am
Night reader wrote:
4GMAT_Mumbai wrote:Hi,

Thanks for the interesting Q ...

1. The x intercept could either be -ve or +ve as it entirely depends on the value of r. If the line meets the x-axis at (a,0);

then the slope = (6-0) / (r - a) = -0.5

12 = a-r.

Whether a is +ve or not depends on r. Hence, insuff ...

2. r > 0.

then slope = (6-0) / (r - a) = some -ve number

So, r - a < 0

a > r

a > a positive r.

So, a also has to be +ve.

Answer: B ?
flawless reasoning and correct answer! thanks

BTW, when the e-book of 4gmat on number theory and inequalities will be available? I got one for perms, prob and combin. - awesome stuff
Hi dude. I am facing sum hiccups pn P& C & Probability. Is the E-book of 4GMAT a good buy.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 543
Joined: Tue Jun 15, 2010 7:01 pmFollowed by: 3 members
Thanked: 147 times

by anshumishra » Tue Jan 11, 2011 5:49 am
Anurag@Gurome wrote:
Night reader wrote:In the xy-plane, if line m has negative slope and passes through the point (r; 6), is the x-intercept of line m positive?

(1) The slope of line m is - 1/2
(2) r > 0
Sometimes the problems on coordinate geometry can be easily solved by drawing or visualizing the scenario. This problem is a good example to learn that. See the below figure.
Image

Statement 1: two lines are shown with negative slope (I've not shown the slope as the value of the slope doesn't matter), one of them has positive x-intercept and other one has negative.

Not sufficient

Statement 2: As r is positive, the point (r, 6) lies on the first quadrant. Any line having negative slope and passing through any point on the first quadrant must have a positive x-intercept.

Sufficient.

The correct answer is B.
Nicely done Anurag !
Graphical approach helps a lot. Many a times, it helps us from making silly mistakes.
Thanks
Anshu

(Every mistake is a lesson learned )
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1