GMAT Changed on April 16th - Read about the latest changes here

 It is currently 20 May 2018, 14:37

### 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

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# M13 Q13

Author Message
Manager
Joined: 10 Apr 2008
Posts: 53

### Show Tags

15 Jun 2009, 22:33
Is $$(x - y)*(x + y)$$ an even integer?

1. $$x$$ and $$y$$ are integers
2. $$x + y$$ is even

(C) 2008 GMAT Club - m13#13

* Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
* Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
* BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
* EACH statement ALONE is sufficient
* Statements (1) and (2) TOGETHER are NOT sufficient

Can someone give an example of when B would not be sufficient. If x + y is even, how can x-y not be an even integer?

Director
Joined: 03 Jun 2009
Posts: 757
Location: New Delhi
WE 1: 5.5 yrs in IT

### Show Tags

16 Jun 2009, 01:34
thinkblue wrote:
Can someone give an example of when B would not be sufficient. If x + y is even, how can x-y not be an even integer?

In B, its given that x+y is even integer. But we don't know if individually x or y is integer or not.
r.g. x = 1.8 and y=0.2
=> x+y = 2.0, an even integer
and x-y = 1.6, not an integer
the product would also be not an integer.

Together from 1 and 2, we can say that (x - y)*(x + y) is even. Hence IMO C
_________________
Re: M13 Q13   [#permalink] 16 Jun 2009, 01:34
Display posts from previous: Sort by

# M13 Q13

Moderator: Bunuel

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.