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

It is currently 20 Jul 2019, 15:16

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

Is x > 0? (1) -2x > 0 (2) x^3 < 0

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
B
Joined: 16 Jan 2017
Posts: 60
GMAT 1: 620 Q46 V29
Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post Updated on: 21 Mar 2017, 12:31
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

89% (00:39) correct 11% (00:39) wrong based on 99 sessions

HideShow timer Statistics


Is x > 0?

(1) -2x > 0

(2) x^3 < 0

Originally posted by vmelgargalan on 21 Mar 2017, 12:29.
Last edited by vmelgargalan on 21 Mar 2017, 12:31, edited 1 time in total.
Manager
Manager
avatar
B
Joined: 16 Jan 2017
Posts: 60
GMAT 1: 620 Q46 V29
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post 21 Mar 2017, 12:31
I am confused as to why the answer is D. Because for option 2 x could be positive or negative. So we can't be sure whether x is larger or smaller than 0
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56304
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post 21 Mar 2017, 12:42
CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3853
Location: Canada
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post 21 Mar 2017, 12:54
2
Top Contributor
1
vmelgargalan wrote:
Is x > 0?

(1) -2x > 0

(2) x³ < 0


Target question: Is x > 0?

Statement 1: -2x > 0
Divide both sides by -2 to get: x < 0 (we reverse the inequality symbol because we divided by a NEGATIVE value)
If x < 0, then the answer to our target question is NO, it is not the case that x > 0
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: x³< 0
There are a few ways to handle this. Here's one approach.
Since x³< 0, we can be certain that x ≠ 0, which also means that x² is POSITIVE
If x² is POSITIVE, we can take x³< 0 and divide both sides by x² to get: x < 0
If x < 0, then the answer to our target question is NO, it is not the case that x > 0
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer:

RELATED VIDEO

_________________
Test confidently with gmatprepnow.com
Image
Manager
Manager
avatar
B
Joined: 16 Jan 2017
Posts: 60
GMAT 1: 620 Q46 V29
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post 21 Mar 2017, 16:42
Bunuel wrote:
vmelgargalan wrote:
Is x > 0?

(1) -2x > 0

(2) x^3 < 0

I am confused as to why the answer is D. Because for option 2 x could be positive or negative. So we can't be sure whether x is larger or smaller than 0


How does positive value satisfy x^3 < 0? (positive)^3 > 0 and (negative)^3 < 0.


Yep, you are right. Had a brain fart. It doesn't. Silly, that this was the only wrong question I got... Once again I read the question too fast and I thought both signs were in the same direction.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 11720
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0  [#permalink]

Show Tags

New post 13 Aug 2018, 09:32
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.
_________________
GMAT Club Bot
Re: Is x > 0? (1) -2x > 0 (2) x^3 < 0   [#permalink] 13 Aug 2018, 09:32
Display posts from previous: Sort by

Is x > 0? (1) -2x > 0 (2) x^3 < 0

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





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