Find all School-related info fast with the new School-Specific MBA Forum

It is currently 21 Aug 2014, 12:21

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

GMAT Diagnostic Test Question 15

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Expert Post
1 KUDOS received
Founder
Founder
User avatar
Affiliations: UA-1K, SPG-G, HH-D
Joined: 04 Dec 2002
Posts: 12065
Location: United States (WA)
GMAT 1: 750 Q49 V42
GPA: 3.5
WE: Information Technology (Hospitality and Tourism)
Followers: 2219

Kudos [?]: 8200 [1] , given: 3641

GMAT ToolKit User Premium Member CAT Tests
GMAT Diagnostic Test Question 15 [#permalink] New post 06 Jun 2009, 21:27
1
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

46% (02:20) correct 54% (01:19) wrong based on 289 sessions
GMAT Diagnostic Test Question 15
Field: modules, inequalities
Difficulty: 700


Is K a positive number?

(1) |K^3| + 1 > K
(2) K + 1 > |K^3|

A. Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
B. Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
D. EACH statement ALONE is sufficient
E. Statements (1) and (2) TOGETHER are NOT sufficient
[Reveal] Spoiler: OA

_________________

Founder of GMAT Club

Just starting out with GMAT? Start here... | Want to know your GMAT Score? Try GMAT Score Estimator
Need GMAT Book Recommendations? Best GMAT Books

Co-author of the GMAT Club tests

Have a blog? Feature it on GMAT Club!

Get the best GMAT Prep Resources with GMAT Club Premium Membership


Last edited by Bunuel on 06 Oct 2013, 23:18, edited 3 times in total.
Updated
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesManhattan GMAT Discount Codes
1 KUDOS received
CIO
CIO
avatar
Joined: 02 Oct 2007
Posts: 1218
Followers: 87

Kudos [?]: 650 [1] , given: 334

GMAT ToolKit User GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 01 Jul 2009, 07:14
1
This post received
KUDOS
Explanation:
Official Answer: E

Statement 1 is insufficient. Consider K=1 (the answer is YES) and K=0 (the answer is NO). Both K values hold the inequality true.

Statement 2 is insufficient. The logic is the same as in Statement 2. Consider K=1 (the answer is YES) and K=0 (the answer is NO).

Combining the two statements doesn't give us new information.
_________________

Welcome to GMAT Club! :)
Facebook TwitterGoogle+LinkedIn
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

Get the best GMAT Prep Resources with GMAT Club Premium Membership

1 KUDOS received
CIO
CIO
avatar
Joined: 02 Oct 2007
Posts: 1218
Followers: 87

Kudos [?]: 650 [1] , given: 334

GMAT ToolKit User GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 27 Jul 2009, 00:21
1
This post received
KUDOS
Hi,

The trick here is that 0 is neither positive nor negative. Both K=1 and K=0 satisfy both statements. So we can't be sure if K is positive. Does it make sense? Hope it helps. :)
defoue wrote:
Hi dzyubam would you please explain the case when K=0

Rgds

_________________

Welcome to GMAT Club! :)
Facebook TwitterGoogle+LinkedIn
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

Get the best GMAT Prep Resources with GMAT Club Premium Membership

1 KUDOS received
Manager
Manager
avatar
Joined: 18 Oct 2009
Posts: 53
Location: Alberta, Canada
Schools: Queen's E-MBA
Followers: 0

Kudos [?]: 13 [1] , given: 7

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 23 Jan 2010, 21:32
1
This post received
KUDOS
Hi,

In both the cases only 0 & 1 have been considered as values of x. Why not higher values like 2 or 3?
Or, fractional values like -1/2? In case K=-1/2, then 2nd equation is true.

-1/2 + 1 = 1/2
|(-1/2)^3| = 1/8, and 1/2>1/8, i.e. K+1>|K^3|.

Am I grossly wrong in assuming that K can be a fractional number? :?
Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4668
Location: Pune, India
Followers: 1073

Kudos [?]: 4779 [1] , given: 163

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 07 Oct 2011, 03:02
1
This post received
KUDOS
Expert's post
Replying to a pm:

You cannot decide on a particular method for all 'such and such questions'. Your methodology will change according to the question. I anyway do not endorse the positive/negative approach for mod questions. It's very time consuming and there are easier methods available in most cases.
What is the first thing you think about when you see a mod? I think that this term is either 0 or positive.
K^3 is too cumbersome to be dealt algebraically. So I try to deal with it arithmetically.

Is K a positive number? (Or rephrase - Is it that K cannot be 0 or negative?)

(1) |K^3| + 1 > K
0/Positive + Positive > K
K can be positive but of course K can be 0 and negative too here. This relation will still hold. Not sufficient.

(2) K + 1 > |K^3|
K + positive > 0/positive
Here, my first thought is that if K = 0, this relation still holds (and of course it holds for some positive values of K too)
It becomes 0+1 > 0
(Some negative values also satisfy this inequality but I don't need to go there. I need just one value and I got it.)
Not sufficient.

Using both statements, there are positive values of K that satisfy both equations and 0 satisfies them both too. So both together are not sufficient.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Intern
Intern
avatar
Joined: 30 Jun 2009
Posts: 48
Followers: 1

Kudos [?]: 7 [0], given: 2

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 25 Jul 2009, 02:58
Hi dzyubam would you please explain the case when K=0

Rgds
Manager
Manager
avatar
Joined: 08 Jul 2009
Posts: 171
Followers: 0

Kudos [?]: 21 [0], given: 26

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 19 Dec 2009, 13:51
it make sense now. I have got to remember 0.
CIO
CIO
avatar
Joined: 02 Oct 2007
Posts: 1218
Followers: 87

Kudos [?]: 650 [0], given: 334

GMAT ToolKit User GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 25 Jan 2010, 04:10
You're right, K is not limited to integers only. However, if we can be sure it's E using only two values (0 and 1) to verify that, there's no need to test other values (like the fractional values). I hope this makes sense.
siddhartho wrote:
Hi,

In both the cases only 0 & 1 have been considered as values of x. Why not higher values like 2 or 3?
Or, fractional values like -1/2? In case K=-1/2, then 2nd equation is true.

-1/2 + 1 = 1/2
|(-1/2)^3| = 1/8, and 1/2>1/8, i.e. K+1>|K^3|.

Am I grossly wrong in assuming that K can be a fractional number? :?

_________________

Welcome to GMAT Club! :)
Facebook TwitterGoogle+LinkedIn
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 18 Oct 2009
Posts: 53
Location: Alberta, Canada
Schools: Queen's E-MBA
Followers: 0

Kudos [?]: 13 [0], given: 7

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 25 Jan 2010, 05:59
dzyubam wrote:
You're right, K is not limited to integers only. However, if we can be sure it's E using only two values (0 and 1) to verify that, there's no need to test other values (like the fractional values). I hope this makes sense.

siddhartho wrote:
Hi,

then 2nd equation is true.



Thanks for the clarification. But why to limit value of K betyween 0 & 1. In my example if K assumes a value of (-)1/2, then B is true. So we can say from B that K is not positive. IMO ans is B.
CIO
CIO
avatar
Joined: 02 Oct 2007
Posts: 1218
Followers: 87

Kudos [?]: 650 [0], given: 334

GMAT ToolKit User GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 26 Jan 2010, 02:17
Siddhartho, I think you're misunderstanding the Data Sufficiency (DS) questions a bit. When you solve DS questions, you have to be 100% sure that say S1 or S2 is sufficient to answer. That means you have to be able to answer the question with a definite YES or NO using additional info given in S1 and/or S2. If the answer to the question can be either YES or NO, the info from S1 and/or S2 is INSUFFICIENT.

Let's see why B can't be the answer for this question. You're right that the equation from S2 holds true when K=-\frac{1}{2}, but it doesn't make B the right answer. We only know that K can be negative. When you plug K=1 in the same equation, you'll see that it also holds true. Now we know that K can be either negative (-\frac{1}{2}) or positive (1) using S2. Therefore S2 is INSUFFICIENT to answer the question. The answer can't be B.

I hope it helps you. If you're still confused with DS questions, you might want to review the DS section in the Official Guide. There are many very good Math resources on the forums too:
re-new-to-the-math-forum-please-read-this-first-77764.html
_________________

Welcome to GMAT Club! :)
Facebook TwitterGoogle+LinkedIn
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 18 Oct 2009
Posts: 53
Location: Alberta, Canada
Schools: Queen's E-MBA
Followers: 0

Kudos [?]: 13 [0], given: 7

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 26 Jan 2010, 05:41
dzyubam wrote:
That means you have to be able to answer the question with a definite YES or NO using additional info given in S1 and/or S2. If the answer to the question can be either YES or NO, the info from S1 and/or S2 is INSUFFICIENT.

I hope it helps you. If you're still confused with DS questions, you might want to review the DS section in the Official Guide. There are many very good Math resources on the forums too:
re-new-to-the-math-forum-please-read-this-first-77764.html


Thanks very much, I got it now. The 100% concept and the link to resources will both help me.
Intern
Intern
avatar
Joined: 27 Feb 2010
Posts: 6
Followers: 0

Kudos [?]: 4 [0], given: 2

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 01 Mar 2010, 17:47
They ask me if k>0...

Why I cannot assume from the statements that k=0? that would answer the question, right?
CIO
CIO
avatar
Joined: 02 Oct 2007
Posts: 1218
Followers: 87

Kudos [?]: 650 [0], given: 334

GMAT ToolKit User GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 03 Mar 2010, 00:07
Both K=1 and K=0 hold for S1 and S2 (even taken together). This is why you can't assume that K=0. Please see the OE in the second post.

arturocb86 wrote:
They ask me if k>0...

Why I cannot assume from the statements that k=0? that would answer the question, right?

_________________

Welcome to GMAT Club! :)
Facebook TwitterGoogle+LinkedIn
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?

Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Director
Director
avatar
Joined: 21 Dec 2009
Posts: 588
Concentration: Entrepreneurship, Finance
Followers: 15

Kudos [?]: 247 [0], given: 20

GMAT Tests User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 02 Apr 2010, 10:17
I started by testing -1, 0, +1 for both (1) & (2)- got E
But the solution provides that only 0 and 1 are enough test Nos.
Thanks.
_________________

KUDOS me if you feel my contribution has helped you.

Manager
Manager
avatar
Joined: 24 Apr 2010
Posts: 62
Followers: 1

Kudos [?]: 7 [0], given: 0

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 03 Sep 2010, 09:46
he he....i have started thinking that i should not have taken this test at first place...till 14 questions there are around 3-4 such questions .....like preying on exception...i hope in real gmat we dont each question like that....
here i thought it was B
but 0 is taken as positive number which ruins the things...
in another question there was 0!
some confusion regarding 13 as well ...

any way good are good but i have started question myself would it be near real gmat...
Intern
Intern
avatar
Joined: 08 May 2011
Posts: 4
Followers: 0

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

Re: GMAT Diagnostic Test Question 14 [#permalink] New post 13 May 2011, 06:18
basically for these type of questions ...you should always check the equations with values -1 , 0 , 1... most of the times you get through your answer using these...
Senior Manager
Senior Manager
User avatar
Joined: 23 Oct 2010
Posts: 384
Location: Azerbaijan
Concentration: Finance
Schools: HEC '15 (A)
GMAT 1: 690 Q47 V38
Followers: 11

Kudos [?]: 129 [0], given: 73

GMAT ToolKit User
Re: GMAT Diagnostic Test Question 14 [#permalink] New post 14 Oct 2011, 03:23
from stmt 1 & 2 we know that -

k-1<|K^3|<k+1

lets k =-2
then -3<8<-1 not true

lets k=2
1<8<3 not true
lets k=0
-1<0<1 true

E is the answ
_________________

Happy are those who dream dreams and are ready to pay the price to make them come true

Intern
Intern
avatar
Joined: 21 May 2008
Posts: 4
Followers: 0

Kudos [?]: 1 [0], given: 5

Is K a positive number ? [#permalink] New post 09 Feb 2013, 14:06
Statement 1 - |K^3| +1 > k
Statement 2 - k +1 > |K^3|

I disagree with the solution below : Can someone review and let me know if i'm mistaken ?

Statement 1 is insufficient. Consider K=1 (the answer is YES) and K=0 (the answer is NO). Both values hold the inequality true.

Statement 2 is insufficient. The logic is the same as in Statement 2. Consider K=1 (the answer is YES) and K=0 (the answer is NO).

Combining the two statements doesn't give us new information.

The correct answer is E.
Intern
Intern
avatar
Joined: 18 Nov 2011
Posts: 37
Concentration: Strategy, Marketing
GMAT Date: 06-18-2013
GPA: 3.98
Followers: 0

Kudos [?]: 4 [0], given: 0

Re: Is K a positive number ? [#permalink] New post 09 Feb 2013, 15:46
anartey wrote:
Statement 1 - |K^3| +1 > k
Statement 2 - k +1 > |K^3|

I disagree with the solution below : Can someone review and let me know if i'm mistaken ?

Statement 1 is insufficient. Consider K=1 (the answer is YES) and K=0 (the answer is NO). Both values hold the inequality true.

Statement 2 is insufficient. The logic is the same as in Statement 2. Consider K=1 (the answer is YES) and K=0 (the answer is NO).

Combining the two statements doesn't give us new information.

The correct answer is E.


Statement 1:
If K=0 then |k^3|+1 = 1 --- Yes
If K=-1 then |k^3|+1 = 0 --- No
S1 is not sufficient

Statement 2:
If K=1 then K+1=2 and |k^3|=1 --- Yes
If K=-1 thenK+1=0 and |k^3|=1 ---No
S2 is not sufficient

Putting the two together gives no further information
Intern
Intern
avatar
Joined: 07 Sep 2013
Posts: 5
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: GMAT Diagnostic Test Question 15 [#permalink] New post 06 Apr 2014, 12:28
The question asks if k is a positive number? The answer is yes, if k is a positive number. The answer is no, if k is a negative number. Why should you take into consideration, a situation in which k is neither positive nor negative?
Re: GMAT Diagnostic Test Question 15   [#permalink] 06 Apr 2014, 12:28
    Similar topics Author Replies Last post
Similar
Topics:
12 Experts publish their posts in the topic GMAT Diagnostic Test Question 12 bb 28 06 Jun 2009, 21:09
46 Experts publish their posts in the topic GMAT Diagnostic Test Question 8 bb 29 06 Jun 2009, 20:59
21 Experts publish their posts in the topic GMAT Diagnostic Test Question 5 bb 26 06 Jun 2009, 20:07
7 Experts publish their posts in the topic GMAT Diagnostic Test Question 2 bb 26 06 Jun 2009, 18:03
26 Experts publish their posts in the topic GMAT Diagnostic Test Question 1 bb 30 05 Jun 2009, 21:30
Display posts from previous: Sort by

GMAT Diagnostic Test Question 15

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2    Next  [ 21 posts ] 

Moderators: Bunuel, WoundedTiger



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

Powered by phpBB © phpBB Group and phpBB SEO

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®.