Is 2|xy^2|> 0? : Data Sufficiency (DS)

Zarrolou

Director

Joined: 02 Sep 2012

Status:Far, far away!

Posts: 859

Location: Italy

Concentration: Finance, Entrepreneurship

GPA: 3.8

Is 2|xy^2|> 0? [#permalink]

05 May 2013, 10:35

7

Kudos

14

Bookmarks

00:00

A

B

C

D

E

Difficulty:

55% (hard)

Question Stats:

48% (01:00) correct

52% (01:00) wrong

based on 300 sessions

Hide Show timer Statistics

Is 2|xy^2|> 0?

(1) x > 0

(2) xy > 0

Show Answer

Official Answer

Official Answer and Stats are available only to registered users. Register/Login.

request expert reply

Archit143

Director

Joined: 21 Sep 2012

Status:Final Lap Up!!!

Affiliations: NYK Line

Posts: 734

Location: India

Schools: Cox '16 (S) AGSM '16 Tulane '16 (S) McCombs '16 (S) Neeley '16 (S) Jones '16 (S) ISB '15 (D) MIT-LGO '16 (M)

GMAT 1: 410 Q35 V11

GMAT 2: 530 Q44 V20

GMAT 3: 630 Q45 V31

GPA: 3.84

WE:Engineering (Transportation)

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 11:45

Hi
I think the question is flawed....U need to check it again...I may be wrong, If i am than pls correct me!

Consider kudos if my post helps!!!!!

Archit

anish123ster

Intern

Joined: 19 Aug 2012

Posts: 43

Re: Is 2|xy^2|> 0? [#permalink]

Updated on: 05 May 2013, 14:02

3

Kudos

B..
so as to confirm that it equation is not equal to zero..

Originally posted by anish123ster on 05 May 2013, 11:50.
Last edited by anish123ster on 05 May 2013, 14:02, edited 1 time in total.

navkaran

Intern

Joined: 27 Jul 2012

Posts: 25

Schools: Stanford '17 (II) HBS '18 (S) Kellogg '18 Wharton '18 (S) Anderson '18 ISB '17 Sloan '18 CBS

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 13:28

1

Kudos

B
2nd option is necessary
Just need to see if the expression is not 0.
1 alone cant assure that, but 2 alone can

Bluelagoon

Manager

Joined: 21 Jan 2010

Posts: 193

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 15:35

1

Kudos

The given condition will be true if both x and y are not zero. B clearly states that. Hence B.

manishuol

Intern

Joined: 30 Sep 2012

Status:Pushing Hard

Affiliations: GNGO2, SSCRB

Posts: 44

Location: India

Concentration: Finance, Entrepreneurship

GPA: 3.33

WE:Analyst (Health Care)

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 20:35

4

Kudos

Zarrolou wrote:

Is \(2|xy^2|> 0\)?

A)\(x>0\)

B)\(xy>0\)

This is a DS I created, I'll post the OA and the OE after some discussion

If you want give it a try, Kudos to the first user(s) who got it right!

This Q . asks Is \(2|xy^2|> 0\)? or \(|xy^2|> 0\)?

Statement :: 1 --- > \(x>0\) .. Dont't Know the value of Y ,.... It can be integer or 0 as well. Therefore, Insufficient.

Statement :: 2--- > \(xy>0\) ........ This means that either of them has +ve signs or -ve signs. Because for both the cases the condition ...\(xy>0\) must be true. & if we use these values in the Q, stem... The result must be same for both the signs. Therefore, Sufficient.

Hence ................ B .

Archit143

Director

Joined: 21 Sep 2012

Status:Final Lap Up!!!

Affiliations: NYK Line

Posts: 734

Location: India

Schools: Cox '16 (S) AGSM '16 Tulane '16 (S) McCombs '16 (S) Neeley '16 (S) Jones '16 (S) ISB '15 (D) MIT-LGO '16 (M)

GMAT 1: 410 Q35 V11

GMAT 2: 530 Q44 V20

GMAT 3: 630 Q45 V31

GPA: 3.84

WE:Engineering (Transportation)

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 21:13

1

Kudos

missed the point that y could be equal to 0....Of course anopther vote for B

Archit

B

mau5

Verbal Forum Moderator

Joined: 10 Oct 2012

Posts: 485

Re: Is 2|xy^2|> 0? [#permalink]

05 May 2013, 22:05

1

Kudos

Zarrolou wrote:

Is \(2|xy^2|> 0\)?

A)\(x>0\)

B)\(xy>0\)

This is a DS I created, I'll post the OA and the OE after some discussion

If you want give it a try, Kudos to the first user(s) who got it right!

The question is asking , IS a mod quantity >0? This will always be true, unless there is a possibility that this mod quantity CAN be zero.

From F.S 1, we know that only x>0. y can be 0, in which case we get a NO and y can be a non-zero number, in which case we get a YES. Insufficient.

From F.S 2, we know that xy>0. Thus, both x and y are non-zero numbers. Sufficient.

B.
_________________

All that is equal and not-Deep Dive In-equality

Hit and Trial for Integral Solutions

Signature Read More

AbuRashid

Intern

Joined: 05 May 2013

Posts: 5

Re: Is 2|xy^2|> 0? [#permalink]

06 May 2013, 03:00

1

Kudos

Answer is B. for S1, the left side cannot be less than zero but certainly it can be zero if y = 0.

Zarrolou

Director

Joined: 02 Sep 2012

Status:Far, far away!

Posts: 859

Location: Italy

Concentration: Finance, Entrepreneurship

GPA: 3.8

Re: Is 2|xy^2|> 0? [#permalink]

06 May 2013, 03:22

1

Bookmarks

Good job guys!

The OA in indeed B.

\(|abs|\) can be \(\geq{0}\), so to make sure that is \(>\) we need to enstablish that both x,y are \(\neq{0}\)

B does just that

Bluelagoon

Manager

Joined: 21 Jan 2010

Posts: 193

Re: Is 2|xy^2|> 0? [#permalink]

08 May 2013, 13:37

Zarrolou wrote:

Is 2|xy^2|> 0?

(1) x > 0

(2) xy > 0

Absolute values are always greater than equal to zero. So, the question is asking if both x and y are not zero.
1)No mention of y .
2)Both are positive or negative but not zero. That's what we want to know. SUFFICIENT.

krrish

Intern

Joined: 04 Mar 2013

Posts: 47

Location: India

Concentration: General Management, Marketing

Schools: Booth '16 Kellogg '14 Stanford '14 Sloan '14

GPA: 3.49

WE:Web Development (Computer Software)

Re: Is 2|xy^2|> 0? [#permalink]

16 May 2013, 09:22

Zarrolou wrote:

Is 2|xy^2|> 0?

(1) x > 0

(2) xy > 0

Stmt 1 is not sufficient,
consider stmt2: sy is positive so no matter what ever may be the value of x, its in mod so its positive :: sufficient.
B. is the answer

Reaper

Intern

Joined: 31 May 2013

Posts: 10

Re: Is 2|xy^2|> 0? [#permalink]

23 Jun 2013, 08:38

1

Kudos

Not clear about B.

If we open the modulus we arrive at different values

for xy > 0

x < 0, y < 0 then xy^2 < 0
x > 0, y > 0 then xy^2 > 0

Zarrolou

Director

Joined: 02 Sep 2012

Status:Far, far away!

Posts: 859

Location: Italy

Concentration: Finance, Entrepreneurship

GPA: 3.8

Re: Is 2|xy^2|> 0? [#permalink]

23 Jun 2013, 08:45

shivdeepmodi wrote:

Not clear about B.

If we open the modulus we arrive at different values

for xy > 0

x < 0, y < 0 then xy^2 < 0
x > 0, y > 0 then xy^2 > 0

No matter what sign \(xy^2\) has, when we apply the mod it will become positive.

There is only one case in which this does not happen, and it's the case where \(xy=0\) => \(|xy^2|=0\).
With option B we are sure that neither x nor y is zero, so the expression \(2|xy^2|\) will be positive.

There is no need to open the abs value, all we need to check is whether x and y are not zero numbers => B does that and it's sufficient.

Hope it's clear

tchang

Intern

Joined: 07 Sep 2013

Posts: 22

Concentration: Entrepreneurship

GPA: 3.52

Re: Is 2|xy^2|> 0? [#permalink]

15 Sep 2013, 17:40

1

Bookmarks

Since there's an absolute value symbol in the question, the ONLY time the left side ISN'T > 0 is when it EQUALS 0

So, if x or y = 0, then the answer is NO
If neither x nor y = 0, then the answer is YES

1) x > 0

x is positive, but we don't know about y
If y = 0, then NO
If y = anything else, then YES
Insufficient

2) xy > 0

x and y are either both positive or both negative. Neither can be 0 so the answer is always YES
Sufficient

Choose

Show Spoiler

B

t1000

B

srinjoy1990

Manager

Joined: 04 Feb 2016

Posts: 51

Location: India

Concentration: Technology, Marketing

Schools: S.P.Jain Institute (A)

GMAT 1: 650 Q48 V32

GPA: 4

WE:Sales (Computer Software)

Is 2|xy^2|> 0? [#permalink]

02 May 2018, 13:45

I somehow don't find the question convincing.

2|xy^2|> 0

note that y^2 > 0 for any real value of y. We do not consider imaginary values in gmat. If so,
then,

2|xy^2|> 0 => |x| > 0. [Note that |x| > 0 for any value except 0, x belongs to {(-inf, inf) - 0}]

If so, then the answer cannot be B.

B states xy > 0 This means x > 0 and y >0 or x< 0 and y <0. If y <0 then x <0. So in any case |x| > 0 since |x| != 0.

Then inequality does not depend on the value of y in anyway. IMO D.

L

Mo2men

RSM Erasmus Moderator

Joined: 26 Mar 2013

Posts: 2462

Concentration: Operations, Strategy

Schools: Erasmus (II)

Re: Is 2|xy^2|> 0? [#permalink]

02 May 2018, 14:32

1

Kudos

srinjoy1990 wrote:

I somehow don't find the question convincing.

2|xy^2|> 0

note that y^2 > 0 for any real value of y. We do not consider imaginary values in gmat. If so,
then,

2|xy^2|> 0 => |x| > 0. [Note that |x| > 0 for any value except 0, x belongs to {(-inf, inf) - 0}]

If so, then the answer cannot be B.

B states xy > 0 This means x > 0 and y >0 or x< 0 and y <0. If y <0 then x <0. So in any case |x| > 0 since |x| != 0.

Then inequality does not depend on the value of y in anyway. IMO D.

y^2 could equal to zero too. i.e. y = 0. Hence the answer is to question is No. If y is any number then answer would be yes.

B

srinjoy1990

Manager

Joined: 04 Feb 2016

Posts: 51

Location: India

Concentration: Technology, Marketing

Schools: S.P.Jain Institute (A)

GMAT 1: 650 Q48 V32

GPA: 4

WE:Sales (Computer Software)

Re: Is 2|xy^2|> 0? [#permalink]

02 May 2018, 14:39

Missed it you are right!

bumpbot

Non-Human User

Joined: 09 Sep 2013

Posts: 32544

Re: Is 2|xy^2|> 0? [#permalink]

23 Jul 2023, 09:06

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.
_________________

Signature Read More

gmatclubot

Re: Is 2|xy^2|> 0? [#permalink]

23 Jul 2023, 09:06

GMAT Data Sufficiency (DS) Questions

Is 2|xy^2|> 0?

GMAT Question Banks