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 →

equations

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 659
Joined: Mon Dec 14, 2009 8:12 amFollowed by: 3 members
Thanked: 32 times
by Gurpinder » Wed Sep 15, 2010 11:09 am
What is the value of b + c ?
(1) ab + cd + ac + bd = 6
(2) a + d = 4

[spoiler]oa: (C)[/spoiler]


[spoiler]the first one can be factored to a(b+c)+d(c+b)=6

does this mean that (a+d)+(c+b)=6???

and then simply plugin the value from (2) ???[/spoiler]


please explain!

thx.
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 509
Joined: Wed Apr 21, 2010 1:08 pmFollowed by: 85 members
Location: Irvine, CA
Thanked: 199 times
GMAT Score:750

by tpr-becky » Wed Sep 15, 2010 11:43 am
you are correct that the first one can be factored to a(b+c) + d(b+c)=6 but your second equation is incorrect. from the previous equation we can factor out a (b+c) to get (b+c)(a+d). but this still doesn't help becuase we don't know a+d.

left with BCE

STatement 2 doesn't give you enough information by iself becuase we still have b and c undefined. Left with C or E.

Together, after the equation from statement one is factored we get (b+c)(a+d)=6 and (a+d)=4 which means (b+c)(4)=6 and from there we can solve it which means this is sufficient.

choose C.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 659
Joined: Mon Dec 14, 2009 8:12 amFollowed by: 3 members
Thanked: 32 times

by Gurpinder » Wed Sep 15, 2010 11:53 am
Thx Becky!
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1