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 →

Bea's CDs

Expert replies
Post new topic Post Reply
Previous Topic Next Topic

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 » Thu Jan 29, 2009 2:21 pm
Bea owns how many more CDs than Al owns?
(1) If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

Please note that this is not an official GMAT question; it’s my attempt to create difficult (650+ level) GMAT-style questions for this forum.
Last edited by Brent@GMATPrepNow on Thu Jan 29, 2009 6:49 pm, edited 1 time in total.
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
User avatar
Community Manager
Posts: 1049
Joined: Sun Apr 06, 2008 5:15 pmFollowed by: 27 members
Location: Pittsburgh, PA
Thanked: 113 times
GMAT Score:710

by dmateer25 » Thu Jan 29, 2009 5:57 pm
Brent,

Is statement one supposed to be: If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns?


If so, I will go with B.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

B = Bea
A = Al

B-1 = A + 1 + 4
B = A + 6

Bea owns 6 more cd's than al
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 » Thu Jan 29, 2009 6:49 pm
Is statement one supposed to be: If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns?
Oops. Yes, you're exactly right, dmateer25. Right about the wording (which I have now changed) and right about the answer (B).

Here's my full solution as well:

Let A = number of CDs Al has and let B = number of CDs Bea has.
We want to determine the value of B – A

(1) We can create the equation 2(B-9) = A+9
Simplify this to get 2B-18= A+9
Or 2B-A=27
This does not tell us the value of B-A. INSUFF.

(2) We can create the equation B-1 = A+1+4
Simplify this to get B-A= 6
SUFF (Bea has 6 CDs more than Al has)

Answer = B
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: 38
Joined: Tue Jan 27, 2009 10:24 am

Re: Bea's CDs

by sanjay_dce » Fri Jan 30, 2009 11:03 pm
Brent Hanneson wrote:Bea owns how many more CDs than Al owns?
(1) If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

Please note that this is not an official GMAT question; it’s my attempt to create difficult (650+ level) GMAT-style questions for this forum.



an easy/quick way to solve such kind of DS question is:
the question stem ask about diff b/w B and A.

1) stmt1 gives an equation but in multiple terms of one of the variable A hence A-B can't be found out( no common factor)
2) stmt 2 gives a equation where there is no multiplier of A or B hence B-A can be found out. it will take 5-10 seconds atmost if such thinking is realised

hence Ans is B
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 208
Joined: Sat Jan 31, 2009 11:32 am
Location: Mumbai
Thanked: 2 times

by vikram_k51 » Tue Feb 03, 2009 7:37 am
Bea owns how many more CDs than Al owns?
(1) If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

From A: 2x-y=27;Not Sufficient

From B: x-y=6;Sufficient

Hence B
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1