It is currently 23 Sep 2017, 09:59

Happening Now:

Alleviate MBA app anxiety! Come to Chat Room #2

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

M16 Q18

Author Message
CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2764

Kudos [?]: 1856 [1], given: 235

Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35

Show Tags

04 Apr 2010, 13:49
1
KUDOS
I think the ans should be E, as y =0 and x as odd integer case is not considered.

Attachments

1.jpeg [ 31.38 KiB | Viewed 1213 times ]

_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned

Jo Bole So Nihaal , Sat Shri Akaal

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Kudos [?]: 1856 [1], given: 235

CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2764

Kudos [?]: 1856 [0], given: 235

Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35

Show Tags

05 Apr 2010, 14:06
Bump.... BB could u pls check this.
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned

Jo Bole So Nihaal , Sat Shri Akaal

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Kudos [?]: 1856 [0], given: 235

Math Expert
Joined: 02 Sep 2009
Posts: 41698

Kudos [?]: 124616 [0], given: 12079

Show Tags

05 Apr 2010, 17:24
gurpreetsingh wrote:
I think the ans should be E, as y =0 and x as odd integer case is not considered.

In case $$x=odd$$ and $$y=0$$ --> $$2*x*5*y=0=even$$

Question: $$2*x*5*y=even$$. As there is 2 as a multiple, then this expression will be even if $$5xy=integer$$. Basically we are asked is $$5xy=integer$$ true?

Note that $$x$$ and $$y$$ may not be integers for $$2*x*5*y$$ to be even (example $$x=\frac{7}{9}$$ and $$y=\frac{9}{7}$$) BUT if they are integers then $$2*x*5*y$$ is even.

(1) $$2+x+5+y=even$$ --> $$7+x+y=even$$ --> $$x+y=odd$$. Not sufficient. (x=1 and y=2 answer YES BUT x=1.3 and y=1.7 answer NO)

(2) $$x-y=odd$$. Not sufficient. (x=1 and y=2 answer YES BUT x=1.3 and y=0.3 answer NO)

(1)+(2) Sum (1) and (2) $$(x+y)+(x-y)=odd_1+odd_2$$ --> $$2x=even$$ --> $$x=integer$$ --> $$y=integer$$ --> Both $$x$$ and $$y$$ are integers. Hence sufficient.

_________________

Kudos [?]: 124616 [0], given: 12079

Re: M16 Q18   [#permalink] 05 Apr 2010, 17:24
Similar topics Replies Last post
Similar
Topics:
m09 Q 18 3 08 Aug 2010, 14:05
m09 Q 18 2 17 Apr 2011, 12:57
2 m11 Q18 8 26 May 2014, 09:39
5 m10 q18 16 04 Apr 2014, 05:17
1 m07q18 16 11 Jul 2010, 05:44
Display posts from previous: Sort by

M16 Q18

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®.