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 →

geometry in DS...

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
User avatar
Master | Next Rank: 500 Posts
Posts: 158
Joined: Sat Sep 03, 2011 10:31 amFollowed by: 2 members
Thanked: 29 times

by gmatclubmember » Tue Sep 06, 2011 6:57 am
mukgera wrote:In the xy-plane, does the line with equation y = 3x + 2 contains the point (r,s)?

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

OA after some discussion.[/quote-

---------------
r and s should satisfy the eqution of line. so s=3r+2.
Put that value in 1 and it satisfy the condition.
Similary put the same value in 2 and it too satisfy the condition.

So both statements are sufficient to answer the question.

D.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Tue Sep 06, 2011 7:10 am
mukgera wrote:In the xy-plane, does the line with equation y = 3x + 2 contains the point (r,s)?
1) (3r+2-s)(4r+9-s) = 0
2) (4r-6-s)(3r+2-s) = 0
If (r,s) is on the line, then it must be the case that s = 3r+2
So, the target question can be reworded as "Does s = 3r+2"

(1) If (3r+2-s)(4r+9-s) = 0, then either a) 3r+2-s = 0 or b) 4r+9-s = 0

a) If 3r+2-s = 0 then s = 3r+2 (yes!)
b) If 4r+9-s = 0 then s= 4r+9 (no!)
Insufficient

(2) If (4r-6-s)(3r+2-s) = 0, then either c) 4r-6-s or d) 3r+2-s = 0
c) If 4r-6-s=0 then s = 4r-6 (no!)
d) If 3r+2-s = 0 then s = 3r+2 (yes!)
Insufficient

If statements (1) and (2) are true, then it must be the case that s = 3r+2, in which case (r,s) IS on the line.

Answer is C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 158
Joined: Sat Sep 03, 2011 10:31 amFollowed by: 2 members
Thanked: 29 times

by gmatclubmember » Tue Sep 06, 2011 7:27 am
Brent@GMATPrepNow wrote:
mukgera wrote:In the xy-plane, does the line with equation y = 3x + 2 contains the point (r,s)?
1) (3r+2-s)(4r+9-s) = 0
2) (4r-6-s)(3r+2-s) = 0
If (r,s) is on the line, then it must be the case that s = 3r+2
So, the target question can be reworded as "Does s = 3r+2"

(1) If (3r+2-s)(4r+9-s) = 0, then either a) 3r+2-s = 0 or b) 4r+9-s = 0

a) If 3r+2-s = 0 then s = 3r+2 (yes!)
b) If 4r+9-s = 0 then s= 4r+9 (no!)
Insufficient

(2) If (4r-6-s)(3r+2-s) = 0, then either c) 4r-6-s or d) 3r+2-s = 0
c) If 4r-6-s=0 then s = 4r-6 (no!)
d) If 3r+2-s = 0 then s = 3r+2 (yes!)
Insufficient

If statements (1) and (2) are true, then it must be the case that s = 3r+2, in which case (r,s) IS on the line.

Answer is C

Cheers,
Brent

Thanks for pointing out my mistake.
In this case we would need both the conditions to arrive at the conclusion that s = 3r+2 and so the answer should be C.

(3r+2-s)(4r+9-s) = (4r-6-s)(3r+2-s) , if 3r+2-s!=0 then 9=-6 which is incorrect so 3r+2-s has to be 0 and then it would satisfy the equation.

Is that correct.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Tue Sep 06, 2011 7:37 am
(3r+2-s)(4r+9-s) = (4r-6-s)(3r+2-s) , if 3r+2-s!=0 then 9=-6 which is incorrect so 3r+2-s has to be 0 and then it would satisfy the equation.
You're absolutely correct, gmatclubmember.

Although, for the benefit of others, I should point out that by "!=0" you mean "not equal to zero".

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 77
Joined: Tue Aug 16, 2011 11:49 pm
Thanked: 3 times

by mukgera » Tue Sep 06, 2011 8:53 am
Thanks Brent for this wonderful explanation...OA is C
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1