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 →

GMATPrep Arithmetic

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 1153
Joined: Wed Jun 20, 2007 6:21 amFollowed by: 2 members
Thanked: 146 times

Re: GMATPrep Arithmetic

by parallel_chase » Sat Jul 19, 2008 3:15 pm
caramel3536 wrote:If R = 1 + 2xy +x(squared)y(squared)
What is the value of xy
(1) R = 0
(2) x>0

Ans = A
The answer is indeed A

R=1+2xy+x^2y^2 => (1+xy)^2

Statement I

R=0, therefore (1+xy)^2=0
xy=-1

Statement II
x>0

It does not gives us any specific value of x or y or R

Not Sufficient.


Hence A.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 58
Joined: Sat Feb 02, 2008 10:13 pm

by caramel3536 » Sun Jul 20, 2008 6:44 pm
Thanks
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 941
Joined: Sun Dec 27, 2009 12:28 amFollowed by: 1 member
Thanked: 20 times

by bhumika.k.shah » Wed Feb 03, 2010 10:55 am
parallel_chase wrote:
R=1+2xy+x^2y^2 => (1+xy)^2

Statement I

R=0, therefore (1+xy)^2=0
xy=-1
Hi, could you explain me the boldfaced part???
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1560
Joined: Tue Nov 17, 2009 2:38 amFollowed by: 5 members
Thanked: 137 times

by thephoenix » Wed Feb 03, 2010 11:00 am
bhumika.k.shah wrote:
parallel_chase wrote:
R=1+2xy+x^2y^2 => (1+xy)^2

Statement I

R=0, therefore (1+xy)^2=0
xy=-1
Hi, could you explain me the boldfaced part???
sq of any non zero no. will be a non zero number only
since after squaring the no. is zero -----> the no. itself is zero---->1+xy=0---->xy=-1
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 941
Joined: Sun Dec 27, 2009 12:28 amFollowed by: 1 member
Thanked: 20 times

by bhumika.k.shah » Wed Feb 03, 2010 7:55 pm
thephoenix wrote:
sq of any non zero no. will be a non zero number only
since after squaring the no. is zero -----> the no. itself is zero---->1+xy=0---->xy=-1
Again this is what i wanted to learn. The concept. THanks :-)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 165
Joined: Wed Mar 24, 2010 8:02 amFollowed by: 1 member
Thanked: 2 times

by HPengineer » Sat Dec 25, 2010 12:02 pm
I solved this by saying X^2 x Y^2 = A

Then saying A^2 + 2A +1 = 0

(A + 1 ) (A +1)

A = -1 so XY = -1

Is this safe?
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 » Sat Dec 25, 2010 12:22 pm
HPengineer wrote:I solved this by saying X^2 x Y^2 = A

Then saying A^2 + 2A +1 = 0

(A + 1 ) (A +1)

A = -1 so XY = -1

Is this safe?
Yes, it is safe.
I guess you meant to write : xy = A. (not X^2*Y^2=A).
Last edited by anshumishra on Sat Dec 25, 2010 5:21 pm, edited 1 time in total.
Thanks
Anshu

(Every mistake is a lesson learned )
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 165
Joined: Wed Mar 24, 2010 8:02 amFollowed by: 1 member
Thanked: 2 times

by HPengineer » Sat Dec 25, 2010 5:20 pm
u got where i was going! Thanks!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1