BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

1000 DS

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Tue Mar 30, 2010 11:36 am

1000 DS

by crackgmat800 » Fri Jun 25, 2010 2:09 pm
If ☉ denotes a mathematical operation, does
x☉y=y☉x for all x and y?

(1) For all x and y, x☉y = 2(x2 + y2).
(2) For all y, 0☉y = 2 y2


Please explain. Will post OA later.
Top
Source: — Data Sufficiency |
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Sat Mar 08, 2008 8:47 pm

by byby030384 » Fri Jun 25, 2010 3:38 pm
Answer: A.
Top
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

by selango » Fri Jun 25, 2010 9:49 pm
X☉Y=Y☉X

From stmt1,

X☉Y=2(X^2+Y^2)

Y☉X=2(Y^2+X^2)

Hence X☉Y=Y☉X

From stmt2,we cannot determine X

Hence A
Top
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Tue Mar 30, 2010 11:36 am

by crackgmat800 » Sat Jun 26, 2010 2:50 am
thanks..
Top
Post new topic Post Reply
• Page 1 of 1