It is currently 21 Oct 2017, 00:08

### 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

# If x # y = –1, which of the following could be true?

Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 03 Mar 2010
Posts: 422

Kudos [?]: 361 [0], given: 22

Schools: Simon '16 (M)
If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

14 Sep 2011, 06:48
00:00

Difficulty:

55% (hard)

Question Stats:

56% (01:28) correct 44% (01:35) wrong based on 63 sessions

### HideShow timer Statistics

x#y= (x−y)^2, if x>y
x#y= x+$$y/4$$, if x≤y

If x # y = –1, which of the following could be true?

I. x=y
II. x>y
III. x<y

(A) I only
(B) II only
(C) III only
(D) I and III only
(E) I, II, and III
[Reveal] Spoiler: OA

_________________

My dad once said to me: Son, nothing succeeds like success.

Kudos [?]: 361 [0], given: 22

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1964

Kudos [?]: 2051 [0], given: 376

Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

14 Sep 2011, 08:09
As always, post your timing for below question, if possible.

x#y= (x−y)^2, if x>y
x#y= x+$$y/4$$, if x≤y

If x # y = –1, which of the following could be true?
I. x=y
II. x>y
III. x<y
(A) I only
(B) II only
(C) III only
(D) I and III only
(E) I, II, and III

(2:05)

A square can never be -ve, ruled out II.

For x=y;

x+x/4=-1; 5x=-4; x=-4/5. Possible

For x>y
x+y/4=-1

x=-1-y/4=-(y+4)/4; y=-4, x=0. Possible.

Ans: "D"
_________________

Kudos [?]: 2051 [0], given: 376

Senior Manager
Joined: 03 Mar 2010
Posts: 422

Kudos [?]: 361 [1], given: 22

Schools: Simon '16 (M)
Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

14 Sep 2011, 08:25
1
KUDOS
fluke wrote:
For x>y
x+y/4=-1

x=-1-y/4=-(y+4)/4; y=-4, x=0. Possible.

This should be x<y.
Other than that flawless.

This custom character sometimes puzzles me.
_________________

My dad once said to me: Son, nothing succeeds like success.

Kudos [?]: 361 [1], given: 22

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1964

Kudos [?]: 2051 [0], given: 376

Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

14 Sep 2011, 08:39
fluke wrote:
For x>y
x+y/4=-1

x=-1-y/4=-(y+4)/4; y=-4, x=0. Possible.

This should be x<y.
Other than that flawless.

This custom character sometimes puzzles me.

That's right. thanks
_________________

Kudos [?]: 2051 [0], given: 376

Senior Manager
Joined: 11 May 2011
Posts: 355

Kudos [?]: 120 [0], given: 46

Location: US
Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

14 Sep 2011, 14:16
Time: 1:00 min.

Approach -
Since, x # y = –1
=> x#y= (x−y)^2, if x>y - This equation is not possible becasue any square will yield positive value.
=> x#y= x+y/4, if x≤y - This equation is only possible and as it says - x≤y, Hence - D.

Cheers!
_________________

-----------------------------------------------------------------------------------------
What you do TODAY is important because you're exchanging a day of your life for it!
-----------------------------------------------------------------------------------------

Kudos [?]: 120 [0], given: 46

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16609

Kudos [?]: 273 [0], given: 0

Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

09 Aug 2017, 00:14
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 273 [0], given: 0

Senior Manager
Joined: 15 Jan 2017
Posts: 282

Kudos [?]: 21 [0], given: 623

Re: If x # y = –1, which of the following could be true? [#permalink]

### Show Tags

17 Aug 2017, 22:58
x#y = (x-y)^2 --> this rules out a -ve value (and option which says x > y; becz square can't be -ve)
so x#y = -1; we have to consider next equation --which says x < equal to y

if x+y/4= -1 --> x+y = -4 => either x = y (-2 and -2) or x less than y (y is 0; x is -4)
Thus I and III

Kudos [?]: 21 [0], given: 623

Re: If x # y = –1, which of the following could be true?   [#permalink] 17 Aug 2017, 22:58
Display posts from previous: Sort by