Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 19 Jul 2019, 04:11

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56302
For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x  [#permalink]

Show Tags

New post 21 Aug 2018, 06:24
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

84% (01:18) correct 16% (01:27) wrong based on 34 sessions

HideShow timer Statistics


NUS School Moderator
User avatar
D
Joined: 18 Jul 2018
Posts: 983
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Premium Member Reviews Badge CAT Tests
For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x  [#permalink]

Show Tags

New post 21 Aug 2018, 06:32
Given x?y = (x + y)(x - y) + (y - x)(y + x) + xy
x = \(\sqrt{12}\)
y = \(\sqrt{3}\)
x?y = (\(x^2\)-\(y^2\)) + (\(y^2\)-\(x^2\)) + \(\sqrt{12}\)*\(\sqrt{3}\)
= 12-3 + 3-12 + \(\sqrt{36}\)
= 6

A is the answer.
_________________
Press +1 Kudos If my post helps!
Retired Moderator
avatar
D
Joined: 25 Feb 2013
Posts: 1197
Location: India
GPA: 3.82
GMAT ToolKit User Reviews Badge
Re: For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x  [#permalink]

Show Tags

New post 21 Aug 2018, 06:33
Bunuel wrote:
For all numbers x and y, the operation ? is defined by x?y = (x + y)(x - y) + (y - x)(y + x) + xy. What is the value of \(\sqrt{12}?\sqrt{3}\)?

A. 6
B. 12
C. 18
D. 24
E. 36


\(x?y = (x + y)(x - y) + (y - x)(y + x) + xy\)

\(=>x?y=x^2-y^2+y^2-x^2+xy=xy\)

\(\sqrt{12}?\sqrt{3}=\sqrt{12*3}=6\)

Option A
GMAT Club Bot
Re: For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x   [#permalink] 21 Aug 2018, 06:33
Display posts from previous: Sort by

For all numbers x and y, the operationΦ is defined by x?y = (x + y)(x

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne