|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
18 Feb 2011, 06:41
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
55% (01:20) correct
45%
(01:19)
wrong
based on 157
sessions
History
Date
Time
Result
Not Attempted Yet
Is (x-y)*(x+y) an even integer?
(1) x and y are integers
(2) x+y is even
Could anyone explain why is B not the right answer?
Any number * even = even
so When X+Y is a even number (it doesnt matter what x-y is ?) the entire product will be even.
When statement 2 says x+y may not be an integer at all then how are we assuming that C will be the answer? i.e both the statements are sufficient?
(1) x and y are integers
(2) x+y is even
Could anyone explain why is B not the right answer?
Any number * even = even
so When X+Y is a even number (it doesnt matter what x-y is ?) the entire product will be even.
When statement 2 says x+y may not be an integer at all then how are we assuming that C will be the answer? i.e both the statements are sufficient?
Experience GMAT Club Test Questions
Yes, you've landed on a GMAT Club Tests question
Craving more? Unlock our full suite of GMAT Club Tests here
Want to experience more? Get a taste of our tests with our free trial today
Rise to the challenge with GMAT Club Tests. Happy practicing!
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
Data Sufficiency Forum
18 Feb 2011, 07:05
Kudos
Bookmarks
MRS
The red part is not correct, it should be (any integer)*(even)=(even) (for example 1.3*2=2.6 not an integer at all)
So the answer is C because if x and y are not integers (second statement does not state that), then x+y may be even (statement 2) and (x-y)*(x+y) may not be an integer at all.
Example:
x=1.8 and y=0.2 - answer to the question NO.
x=1.5 and y=0.5 - answer to the question YES.
Statement (1) says that x and y are integers so combined statements guarantee (x-y)*(x+y) being even.
Hope it helps.
