GMAT Changed on April 16th - Read about the latest changes here

It is currently 25 Apr 2018, 21:04

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

Events & Promotions in June
Open Detailed Calendar

M22-03

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44656
M22-03 [#permalink]

Show Tags

New post 16 Sep 2014, 01:15
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

67% (00:48) correct 33% (01:13) wrong based on 103 sessions

HideShow timer Statistics

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44656
Re M22-03 [#permalink]

Show Tags

New post 16 Sep 2014, 01:15
Expert's post
2
This post was
BOOKMARKED
Official Solution:


(1) \(x^4 = |x|\). This statement implies that \(x=-1\), \(x=0\), or \(x=1\). Not sufficient.

(2) \(x^2 \gt x\). Rearrange and factor out \(x\) to get \(x(x-1) \gt 0\). The roots are \(x=0\) and \(x=1\), "\(\gt\)" sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\). Not sufficient.

(1)+(2) The only value of \(x\) from (1) which is in the range from (2) is \(x=-1\). Sufficient.


Answer: C
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 16 Feb 2014
Posts: 7
Re: M22-03 [#permalink]

Show Tags

New post 09 Nov 2014, 21:42
Thanks for Explanation! I did not understand following part

" The roots are x=0 and x=1, \("\gt"\) sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\)."

I thought \(x(x-1) \gt 0\) would mean \(x \gt 0\) and \(x \gt 1\)

Please suggest. Also how did we get -1 as final answer. As per statement (2) \(x \gt 1\).

Thanks

Bunuel wrote:
Official Solution:


(1) \(x^4 = |x|\). This statement implies that \(x=-1\), \(x=0\), or \(x=1\). Not sufficient.

(2) \(x^2 \gt x\). Rearrange and factor out \(x\) to get \(x(x-1) \gt 0\). The roots are \(x=0\) and \(x=1\), "\(\gt\)" sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\). Not sufficient.

(1)+(2) The only value of \(x\) from (1) which is in the range from (2) is \(x=-1\). Sufficient.


Answer: C
Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44656
Re: M22-03 [#permalink]

Show Tags

New post 10 Nov 2014, 02:57
Sky78 wrote:
Thanks for Explanation! I did not understand following part

" The roots are x=0 and x=1, \("\gt"\) sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\)."

I thought \(x(x-1) \gt 0\) would mean \(x \gt 0\) and \(x \gt 1\)

Please suggest. Also how did we get -1 as final answer. As per statement (2) \(x \gt 1\).

Thanks

Bunuel wrote:
Official Solution:


(1) \(x^4 = |x|\). This statement implies that \(x=-1\), \(x=0\), or \(x=1\). Not sufficient.

(2) \(x^2 \gt x\). Rearrange and factor out \(x\) to get \(x(x-1) \gt 0\). The roots are \(x=0\) and \(x=1\), "\(\gt\)" sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\). Not sufficient.

(1)+(2) The only value of \(x\) from (1) which is in the range from (2) is \(x=-1\). Sufficient.


Answer: C


Check links below.

Solving Quadratic Inequalities - Graphic Approach: solving-quadratic-inequalities-graphic-approach-170528.html
Inequality tips: tips-and-hints-for-specific-quant-topics-with-examples-172096.html#p1379270
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 01 Oct 2014
Posts: 23
Re M22-03 [#permalink]

Show Tags

New post 21 Jun 2016, 07:13
I think this is a high-quality question and the explanation isn't clear enough, please elaborate. Not able to understand the explanation
Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44656
Re: M22-03 [#permalink]

Show Tags

New post 21 Jun 2016, 07:18
Senior Manager
Senior Manager
User avatar
S
Joined: 08 Jun 2015
Posts: 482
Location: India
GMAT 1: 640 Q48 V29
Premium Member CAT Tests
Re: M22-03 [#permalink]

Show Tags

New post 27 Dec 2017, 08:31
+1 for C. From the first statement x=-1,0, or 1. From second statement , x<0 or x>1. Each statement alone is not sufficient. Combine the two, x=-1. Hence option C.
_________________

" The few , the fearless "

Intern
Intern
avatar
B
Joined: 13 Oct 2017
Posts: 40
M22-03 [#permalink]

Show Tags

New post 16 Feb 2018, 06:51
Bunuel wrote:
Sky78 wrote:
Thanks for Explanation! I did not understand following part

" The roots are x=0 and x=1, \("\gt"\) sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\)."

I thought \(x(x-1) \gt 0\) would mean \(x \gt 0\) and \(x \gt 1\)

Please suggest. Also how did we get -1 as final answer. As per statement (2) \(x \gt 1\).

Thanks

Bunuel wrote:
Official Solution:


(1) \(x^4 = |x|\). This statement implies that \(x=-1\), \(x=0\), or \(x=1\). Not sufficient.

(2) \(x^2 \gt x\). Rearrange and factor out \(x\) to get \(x(x-1) \gt 0\). The roots are \(x=0\) and \(x=1\), "\(\gt\)" sign means that the given inequality holds true for: \(x \lt 0\) and \(x \gt 1\). Not sufficient.

(1)+(2) The only value of \(x\) from (1) which is in the range from (2) is \(x=-1\). Sufficient.


Answer: C


Check links below.

Solving Quadratic Inequalities - Graphic Approach: http://gmatclub.com/forum/solving-quadr ... 70528.html
Inequality tips: http://gmatclub.com/forum/tips-and-hint ... l#p1379270



Hi Bunuel,

I too have exactly the same question as the previous person...I went through the links provided and still cannot understand why in statement 2, x is not either greater than 0 or greater than 1. I then got confused as to how you got to the answer being x= (-1).

Would really appreciate a breakdown of the above queries please.

Thanks,

Tosin
Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44656
M22-03 [#permalink]

Show Tags

New post 16 Feb 2018, 06:57
Expert's post
1
This post was
BOOKMARKED
ttaiwo wrote:
Hi Bunuel,

I too have exactly the same question as the previous person...I went through the links provided and still cannot understand why in statement 2, x is not either greater than 0 or greater than 1. I then got confused as to how you got to the answer being x= (-1).

Would really appreciate a breakdown of the above queries please.

Thanks,

Tosin


This is explained in detail in the links provided.

x > 0 or x > 1 doe not make any sense. Is x > 0? So, could it be 0.5? Or is x > 1?

\(x(x-1) \gt 0\) --> x and x - 1 have the same sign.

x > 0 and x - 1 > 0 --> x > 0 and x > 1. Simultaneously to be true x > 1 has to be true.
x < 0 and x - 1 < 0 --> x < 0 and x < 1. Simultaneously to be true x < 0 has to be true.

So, \(x(x-1) \gt 0\) is true for x < 0 and x > 1.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 13 Oct 2017
Posts: 40
Re: M22-03 [#permalink]

Show Tags

New post 17 Feb 2018, 03:58
Bunuel wrote:
ttaiwo wrote:
Hi Bunuel,

I too have exactly the same question as the previous person...I went through the links provided and still cannot understand why in statement 2, x is not either greater than 0 or greater than 1. I then got confused as to how you got to the answer being x= (-1).

Would really appreciate a breakdown of the above queries please.

Thanks,

Tosin


This is explained in detail in the links provided.

x > 0 or x > 1 doe not make any sense. Is x > 0? So, could it be 0.5? Or is x > 1?

\(x(x-1) \gt 0\) --> x and x - 1 have the same sign.

x > 0 and x - 1 > 0 --> x > 0 and x > 1. Simultaneously to be true x > 1 has to be true.
x < 0 and x - 1 < 0 --> x < 0 and x < 1. Simultaneously to be true x < 0 has to be true.

So, \(x(x-1) \gt 0\) is true for x < 0 and x > 1.


Thanks a lot...now understood.
Re: M22-03   [#permalink] 17 Feb 2018, 03:58
Display posts from previous: Sort by

M22-03

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

Moderators: chetan2u, Bunuel



cron

GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.