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
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
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

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

OG DS #57

Expert replies
Source: — Data Sufficiency |

by chatekar » Wed Jul 18, 2007 7:52 am
erdnah,

To find the value of 1/X + 1/Y i.e. (X+Y)/XY, so you need two things,
first is X+Y and the second is XY.

Both are given in statement 1 and 2 so you need both the statements together.

Hope this helps

Thanks
Join the discussion

by erdnah » Wed Jul 18, 2007 7:55 am
@chatekar, yeah, i found that information also in the og :)

but what i really want to know is, why i can't multiply the last term with xy, so that i would get x+y = 0!? i feel terrible stupid :x
Join the discussion

by chatekar » Wed Jul 18, 2007 8:27 am
If you are multiplying by xy to get the value of the given expression, then you are changing the value of the given expression.
You can't simply multiply by xy, you also need to divide by xy so that value of the expression doesn't change.

Am I making sense?

Thanks
Join the discussion

by erdnah » Wed Jul 18, 2007 10:59 am
Yeah, of course you do... :roll:
There are days, I should have stayed in bed. :wink:
Join the discussion

OG DS #56

by erdnah » Fri Jul 20, 2007 9:32 am
It seems as if I did the same mistake today again :roll:

When there is x = x², I divided both sides by x. I though I would get 1 = x which seemed to be wonderful in my eyes... but x could also be 0!

What was this time (or as on the problem above) my mistake in thinking?

Hope someone can help me..
Join the discussion

Re: OG DS #56

by bingojohn » Tue Aug 07, 2007 10:59 am
erdnah wrote:It seems as if I did the same mistake today again :roll:

When there is x = x², I divided both sides by x. I though I would get 1 = x which seemed to be wonderful in my eyes... but x could also be 0!

What was this time (or as on the problem above) my mistake in thinking?

Hope someone can help me..
Solve equation:

x^2 = x
x^2 - x = 0
x(x - 1) = 0

x = 0 OR x = 1

hope this helps...
Join the discussion