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
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.

Manhattan DS

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 84
Joined: Sat Oct 03, 2009 1:13 pm
Thanked: 11 times

by djkvakin » Mon Dec 21, 2009 4:45 pm
please edit the post.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 141
Joined: Sat Feb 28, 2009 8:19 am
Thanked: 1 times

by getso » Mon Dec 21, 2009 9:02 pm
Sorry...I have edited the post now..
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pmFollowed by: 252 members
Thanked: 653 times

by papgust » Mon Dec 21, 2009 9:14 pm
IMO A

If square root (xy) is xy, then xy must be equal to 1 as root(1) = 1. But x and y could be any value. The question is x+y?

A. x = -1/2

As x*y = 1, y = 1/x = -2. x+y value can be found out. Sufficient.

B. y not equal to 0. But many possible values are there to satisy x*y=1. Insufficient.

Please share the OA.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
GMAT Instructor
Posts: 1302
Joined: Mon Oct 19, 2009 2:13 pmFollowed by: 164 members
Location: Toronto
Thanked: 539 times
GMAT Score:800

by Testluv » Mon Dec 21, 2009 10:09 pm
getso wrote:If square root of xy = xy, what is the value of x + y?

(1) x = -1/2
(2) y is not equal to zero
The question stem: square root xy = xy, therefore xy = x^2 * y^2

(1) x = -1/2

subbing in:

(-1/2) * y = (1/2)^2 * y^2

or

-y/2 = y^2/4

or

0 = y^2/4 + y/2

multiplying by 4 to eliminate fractions:

0 = 2y + y^2

factoring out y:

0 = y * (2 + y)

y = 0 or -2

Because we have multiple values for y, this statement is insufficient. The second statement is clearly insufficient because it leaves infinite values for y, and there is no info about x. Together, you know that y is -2 and that x is -1/2.

Apart, insufficient; together, sufficient.

Choose C.

@papgust: you forgot to consider that the equation in the question stem is also satisfied if either of x or y are zero. ;)
Kaplan Teacher in Toronto
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pmFollowed by: 252 members
Thanked: 653 times

by papgust » Mon Dec 21, 2009 10:40 pm
Thanks Testluv! My mistake..
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 141
Joined: Sat Feb 28, 2009 8:19 am
Thanked: 1 times

by getso » Tue Dec 22, 2009 10:12 am
Testluv wrote:
getso wrote:If square root of xy = xy, what is the value of x + y?

(1) x = -1/2
(2) y is not equal to zero
The question stem: square root xy = xy, therefore xy = x^2 * y^2

(1) x = -1/2

subbing in:

(-1/2) * y = (1/2)^2 * y^2

or

-y/2 = y^2/4

or

0 = y^2/4 + y/2

multiplying by 4 to eliminate fractions:

0 = 2y + y^2

factoring out y:

0 = y * (2 + y)

y = 0 or -2

Because we have multiple values for y, this statement is insufficient. The second statement is clearly insufficient because it leaves infinite values for y, and there is no info about x. Together, you know that y is -2 and that x is -1/2.

Apart, insufficient; together, sufficient.

Choose C.

@papgust: you forgot to consider that the equation in the question stem is also satisfied if either of x or y are zero. ;)
Thanks testluv.

xy = x^2 * y^2

I made a mistake of cancelling xy, on both sides of xy=x^2*y^2...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
GMAT Instructor
Posts: 1302
Joined: Mon Oct 19, 2009 2:13 pmFollowed by: 164 members
Location: Toronto
Thanked: 539 times
GMAT Score:800

by Testluv » Tue Dec 22, 2009 10:56 am
Hi Shobha,

cancelling xy on both sides ignores the fact that the equation is also satisfied if either of x or y are zero.
Kaplan Teacher in Toronto
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1