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.

DS Hardcore Numbers

Expert replies
Source: — Data Sufficiency |

by pandeyvineet24 » Wed Dec 23, 2009 3:27 pm
Are you sure you got the question right ?. Question stem has 2*X*5*Y, so the product will always be even.
:)
mmslf75 wrote:Is the product 2*X*5*Y an even integer ?

1) 2 + x + 5 + y is an even integer
2) x - y is an odd integer

Answer :: C
Source :: GMATCL


IMO B

Any clue why B is rejected ??
Join the discussion

by rohan_vus » Wed Dec 23, 2009 3:40 pm
Not sure abt the question

But if the question is what it is , then i see X and Y are not mentioned as integers..and answer must be C then

In that case B cant be the answer coz consider X = 1.5 and Y = .5 ( considering any number coz its not mentioned they are integer) then X - Y = 1. which is an odd integer but your expression 2*X*5*Y is not an even integer

But 2*X*5*Y will surely be an an even integer if we can prove X*Y is an integer..

If you take A alone then we see x + Y is an odd integer if X is 1.3 and y is 1.7...so A alone not sufficient

Combining both A and B you can see X - Y = odd integer and X + Y = odd integer then X and Y are definitely integers...But y so , simple reason , use stmnts from A and B ==> ( X + Y) + ( X - Y) = odd + odd = even ==> 2X = even then X got to be an integer ...it X is an integer then Y has to be an integer...
Join the discussion

by papgust » Wed Dec 23, 2009 7:03 pm
Rohan, rightly said. Even i feel that it should be C.
Join the discussion

by mehravikas » Wed Dec 23, 2009 8:51 pm
Why not 'E'?

X = 0, Y = 1or X = 1, Y = 0 would still given the desired result but depending on X and Y the product could be even or odd.
rohan_vus wrote:Not sure abt the question

But if the question is what it is , then i see X and Y are not mentioned as integers..and answer must be C then

In that case B cant be the answer coz consider X = 1.5 and Y = .5 ( considering any number coz its not mentioned they are integer) then X - Y = 1. which is an odd integer but your expression 2*X*5*Y is not an even integer

But 2*X*5*Y will surely be an an even integer if we can prove X*Y is an integer..

If you take A alone then we see x + Y is an odd integer if X is 1.3 and y is 1.7...so A alone not sufficient

Combining both A and B you can see X - Y = odd integer and X + Y = odd integer then X and Y are definitely integers...But y so , simple reason , use stmnts from A and B ==> ( X + Y) + ( X - Y) = odd + odd = even ==> 2X = even then X got to be an integer ...it X is an integer then Y has to be an integer...
Join the discussion

by mmslf75 » Thu Dec 24, 2009 1:56 am
pandeyvineet24 wrote:Are you sure you got the question right ?. Question stem has 2*X*5*Y, so the product will always be even.
:)
mmslf75 wrote:Is the product 2*X*5*Y an even integer ?

1) 2 + x + 5 + y is an even integer
2) x - y is an odd integer

Answer :: C
Source :: GMATCL


IMO B




Any clue why B is rejected ??

The question is right, but not traditional. That's why I have posted here ... ;-)
Join the discussion

by Testluv » Thu Dec 24, 2009 2:03 am
mehravikas wrote:Why not 'E'?

X = 0, Y = 1or X = 1, Y = 0 would still given the desired result but depending on X and Y the product could be even or odd.
rohan_vus wrote:Not sure abt the question

But if the question is what it is , then i see X and Y are not mentioned as integers..and answer must be C then

In that case B cant be the answer coz consider X = 1.5 and Y = .5 ( considering any number coz its not mentioned they are integer) then X - Y = 1. which is an odd integer but your expression 2*X*5*Y is not an even integer

But 2*X*5*Y will surely be an an even integer if we can prove X*Y is an integer..

If you take A alone then we see x + Y is an odd integer if X is 1.3 and y is 1.7...so A alone not sufficient

Combining both A and B you can see X - Y = odd integer and X + Y = odd integer then X and Y are definitely integers...But y so , simple reason , use stmnts from A and B ==> ( X + Y) + ( X - Y) = odd + odd = even ==> 2X = even then X got to be an integer ...it X is an integer then Y has to be an integer...
Vikas,

if either of x or y were zero, then the product of the expression in the question stem would be zero, and zero is an even integer.
Kaplan Teacher in Toronto
Join the discussion

by mehravikas » Thu Dec 24, 2009 2:07 am
God how could I forget that :-(
Testluv wrote:
mehravikas wrote:Why not 'E'?

X = 0, Y = 1or X = 1, Y = 0 would still given the desired result but depending on X and Y the product could be even or odd.
rohan_vus wrote:Not sure abt the question

But if the question is what it is , then i see X and Y are not mentioned as integers..and answer must be C then

In that case B cant be the answer coz consider X = 1.5 and Y = .5 ( considering any number coz its not mentioned they are integer) then X - Y = 1. which is an odd integer but your expression 2*X*5*Y is not an even integer

But 2*X*5*Y will surely be an an even integer if we can prove X*Y is an integer..

If you take A alone then we see x + Y is an odd integer if X is 1.3 and y is 1.7...so A alone not sufficient

Combining both A and B you can see X - Y = odd integer and X + Y = odd integer then X and Y are definitely integers...But y so , simple reason , use stmnts from A and B ==> ( X + Y) + ( X - Y) = odd + odd = even ==> 2X = even then X got to be an integer ...it X is an integer then Y has to be an integer...
Vikas,

if either of x or y were zero, then the product of the expression in the question stem would be zero, and zero is an even integer.
Join the discussion

by Testluv » Thu Dec 24, 2009 2:12 am
Hey, it happens to the best of us! ;)
Kaplan Teacher in Toronto
Join the discussion