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 Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget 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

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

simple one

Expert replies
by allfta » Sun Jun 20, 2010 1:10 am
IF X^2+Y^2=1, is X+Y=1?
(1) Xy =0
(2) Y = 0


Im not sure about accuracy of the OA but it is C
I chose E
Your choice? and explanation plz.

G-look for ur gmat.
Last edited by allfta on Sun Jun 20, 2010 8:12 pm, edited 2 times in total.
Join the discussion
Source: — Data Sufficiency |

by papgust » Sun Jun 20, 2010 7:25 am
I don't like the question itself. The question asks for x+y. And you have the value of x+y in statement I straight away. In real GMAT, you'll never get these kinds of questions. What is the source?
Download GMAT Math and CR questions with Solutions from Instructors and High-scorers:
https://www.beatthegmat.com/download-gma ... 59366.html

-----------

GO GREEN..! GO VEG..!

Daily Quote:
"Stop feeling sorry for the Butcher if you had to go Veg. The butcher can find another job but the poor animal cannot get back its life"
Join the discussion

by Patrick_GMATFix » Sun Jun 20, 2010 10:23 am
papgust wrote:I don't like the question itself. The question asks for x+y. And you have the value of x+y in statement I straight away. In real GMAT, you'll never get these kinds of questions. What is the source?
I agree 100% with papgust. I think you should consider using a different resource for GMAT prep, unless this question is the exception, not the norm.
  • Ask me about tutoring.
Join the discussion

by allfta » Sun Jun 20, 2010 6:26 pm
OMG.
Sorry guyz. the first condition is XY=0 but not X+Y=0
and I chose E.
sorry again.
Last edited by allfta on Sun Jun 20, 2010 8:13 pm, edited 1 time in total.
Join the discussion

by aagar2003 » Sun Jun 20, 2010 7:59 pm
allfta wrote:OMG.
Sorry guyz. the first condition is XY=0 but not X+Y=0
sorry again.
Might want to edit your original post ....

As for the answer,

X^2 + Y^2 = 1 (A circle with radius 1 and center 0,0)
Is X+Y = 1?

(1) XY = 0
X=0, Y=-1 => X+Y = -1
X=0, Y= 1 => X+Y = 1
Therefore, Not Sufficient alone

(2) Y = 0
=> X= +-1
=> X+Y = X = +- 1
Therefore Not sufficient alone

Options A, B and D are out
Let's see C
XY = 0 and Y = 0
=> X = +-1
Therefore, both statements TOGETHER cannot answer the question whether it is +1. It can be -1 as well.

Thus X+Y = +-1

Correct answer is E
Join the discussion