GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 13 Dec 2018, 19:05

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • GMATbuster's Weekly GMAT Quant Quiz, Tomorrow, Saturday at 9 AM PST

     December 14, 2018

     December 14, 2018

     09:00 AM PST

     10:00 AM PST

    10 Questions will be posted on the forum and we will post a reply in this Topic with a link to each question. There are prizes for the winners.
  • The winning strategy for 700+ on the GMAT

     December 13, 2018

     December 13, 2018

     08:00 AM PST

     09:00 AM PST

    What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

Is x^4-x>0?

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

Hide Tags

Manager
Manager
avatar
B
Joined: 03 Oct 2016
Posts: 79
Concentration: Technology, General Management
WE: Information Technology (Computer Software)
Reviews Badge
Is x^4-x>0?  [#permalink]

Show Tags

New post 21 Oct 2016, 09:03
7
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

66% (01:43) correct 34% (01:30) wrong based on 104 sessions

HideShow timer Statistics

Is \(x^{4}\) - x >0 ?

1) x<0
2) \(x^{4} > x^{2}\)

_________________

KINDLY KUDOS IF YOU LIKE THE POST

VP
VP
User avatar
P
Joined: 05 Mar 2015
Posts: 1004
Re: Is x^4-x>0?  [#permalink]

Show Tags

New post 21 Oct 2016, 09:45
idontknowwhy94 wrote:
Is \(x^{4}\) - x >0 ?

1) x<0
2) \(x^{4} > x^{2}\)

Rephrasing
x(x^3-1)>0
----> x<0 or x>1??

1) x<0 ---->suff
2)x^2(x^2-1)>0
x^2(x+1)(x-1)>0
thus -1<x<0 or x>1------->suff

Ans D
SC Moderator
User avatar
D
Joined: 13 Apr 2015
Posts: 1687
Location: India
Concentration: Strategy, General Management
GMAT 1: 200 Q1 V1
GPA: 4
WE: Analyst (Retail)
GMAT ToolKit User Premium Member
Re: Is x^4-x>0?  [#permalink]

Show Tags

New post 21 Oct 2016, 20:02
1
idontknowwhy94 wrote:
Is \(x^{4}\) - x >0 ?

1) x<0
2) \(x^{4} > x^{2}\)


Is \(x^{4}\) - x >0 --> Is \(x^4 > x\) ?

St1: x < 0 --> x^4 is positive and x is negative. --> x^4 > x. Sufficient

St2: \(x^{4} > x^{2}\) --> If x^4 > x^2 then x^4 > x. Sufficient

Answer: D
CEO
CEO
User avatar
P
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2711
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: Is x^4-x>0?  [#permalink]

Show Tags

New post 21 Oct 2016, 20:14
idontknowwhy94 wrote:
Is \(x^{4}\) - x >0 ?

1) x<0
2) \(x^{4} > x^{2}\)


Question: Is \(x^{4}\) - x >0 ?

Here I am solving this question in more of logical approach rather than using more of Maths

x^4 will be greater than x only if
i) x>1 or
ii) x<0 or


Statement 1: x<0
SUFFICIENT

Statement 2: \(x^{4} > x^{2}\)
which is true only if
i) x>1 or
ii) x<-1 hence
SUFFICIENT

Answer: option D
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Retired Moderator
User avatar
B
Joined: 05 Jul 2006
Posts: 1723
GMAT ToolKit User Premium Member
Re: Is x^4-x>0?  [#permalink]

Show Tags

New post 22 Oct 2016, 00:15
idontknowwhy94 wrote:
Is \(x^{4}\) - x >0 ?

1) x<0
2) \(x^{4} > x^{2}\)


from stem is x(x^3-1)>0 true if x>1 or x<0 ...

from 1

x<0 ... suff

from 2

x^2(x^2-1) >0 , thus /x/>1, i.e. x<-1( X<0) or x>1 ..... suff

D
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9156
Premium Member
Re: Is x^4-x>0?  [#permalink]

Show Tags

New post 21 Aug 2018, 08:32
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: Is x^4-x>0? &nbs [#permalink] 21 Aug 2018, 08:32
Display posts from previous: Sort by

Is x^4-x>0?

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.