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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

DS - absolute value

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 1448
Joined: Tue May 17, 2011 9:55 amFollowed by: 53 members
Location: India
Thanked: 375 times

by Frankenstein » Wed Jun 15, 2011 6:17 am
Hi,
From(1):
if x=4, y=2, |x - y| = |x| - |y|
if x=4, y=-2, |x - y| > |x| - |y|
Not sufficient

From(2):As xy<0, |xy| = -xy
case-1 : |x| - |y| < 0
As |x - y| > 0, |x - y| > |x| - |y| always holds

case-2 : |x| - |y| > 0
|x - y|^2 = x^2 + y^2 - 2xy = x^2 + y^2 + 2|xy|
(|x| - |y|)^2 = x^2 + y^2 - 2|xy|
So, |x - y|^2 > (|x| - |y|)^2
So, |x - y| > |x| - |y|
Sufficient

By picking x and y on the number line or by plugin values also, we can solve this.
Hence, B
Cheers!

Things are not what they appear to be... nor are they otherwise
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1325
Joined: Sun Nov 01, 2009 6:24 amFollowed by: 14 members
Thanked: 105 times

by vikram4689 » Wed Jun 15, 2011 7:07 am
A is not required for such a symm. eqn. (can always verify by plugging no.s). Since x & y are of opposite signs (x - y) will always ADD whereas |x| -|y| will always subtract, so B is sufficient.
Premise: If you like my post
Conclusion : Press the Thanks Button ;)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 118
Joined: Wed Mar 16, 2011 1:44 pmFollowed by: 2 members
Location: Canada
GMAT Score:530

by ccassel » Mon Jun 20, 2011 7:05 am
Frankenstein wrote:Hi,
From(2):As xy<0, |xy| = -xy
case-1 : |x| - |y| < 0
As |x - y| > 0, |x - y| > |x| - |y| always holds

case-2 : |x| - |y| > 0
|x - y|^2 = x^2 + y^2 - 2xy = x^2 + y^2 + 2|xy|
(|x| - |y|)^2 = x^2 + y^2 - 2|xy|
So, |x - y|^2 > (|x| - |y|)^2
So, |x - y| > |x| - |y|
Sufficient

B
Frankenstein, Why would you think of squaring both sides of the equation in statement 2?

Thanks,
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1448
Joined: Tue May 17, 2011 9:55 amFollowed by: 53 members
Location: India
Thanked: 375 times

by Frankenstein » Mon Jun 20, 2011 7:25 am
ccassel wrote:
Frankenstein wrote:Hi,
From(2):As xy<0, |xy| = -xy
case-1 : |x| - |y| < 0
As |x - y| > 0, |x - y| > |x| - |y| always holds

case-2 : |x| - |y| > 0
|x - y|^2 = x^2 + y^2 - 2xy = x^2 + y^2 + 2|xy|
(|x| - |y|)^2 = x^2 + y^2 - 2|xy|
So, |x - y|^2 > (|x| - |y|)^2
So, |x - y| > |x| - |y|
Sufficient

B
Frankenstein, Why would you think of squaring both sides of the equation in statement 2?

Thanks,
Hi,
If you go by logic or by plugin method, you don't need to. But, by explaining mathematically, I need to somehow bring xy in the inequality. So, I squared both sides.
Cheers!

Things are not what they appear to be... nor are they otherwise
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1