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

It is currently 15 Feb 2019, 23:28

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 February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Strategy Webinar

     February 16, 2019

     February 16, 2019

     07:00 AM PST

     09:00 AM PST

    Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
  • $450 Tuition Credit & Official CAT Packs FREE

     February 15, 2019

     February 15, 2019

     10:00 PM EST

     11:00 PM PST

    EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)

D01-15

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

Hide Tags

 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
D01-15  [#permalink]

Show Tags

New post 15 Sep 2014, 23:11
1
14
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

60% (01:08) correct 40% (01:10) wrong based on 228 sessions

HideShow timer Statistics

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
Re D01-15  [#permalink]

Show Tags

New post 15 Sep 2014, 23:12
Official Solution:


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 1. Consider \(K=1\) (the answer is YES) and \(K=0\) (the answer is NO).

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


Answer: E
_________________

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: 03 Feb 2015
Posts: 14
GMAT 1: 680 Q47 V36
GMAT 2: 720 Q49 V39
Re: D01-15  [#permalink]

Show Tags

New post 16 Mar 2015, 21:48
hi Bunuel

you wrote-
'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).'


In [highlight]statement 2
if we put value k=0 we will get 1>0. which is true. how is this a No
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
Re: D01-15  [#permalink]

Show Tags

New post 17 Mar 2015, 04:33
harDill wrote:
hi Bunuel

you wrote-
'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).'


In [highlight]statement 2
if we put value k=0 we will get 1>0. which is true. how is this a No


The questions asks whether k is a positive number. For (2) if k = 1 (which satisfies second statement) it IS a positive number but if k = 0 (which also satisfies second statement) it is NOT a positive number (0 is not a positive number, it's neither positive nor negative).
_________________

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

Manager
Manager
User avatar
S
Joined: 11 Sep 2013
Posts: 145
Concentration: Finance, Finance
Re: D01-15  [#permalink]

Show Tags

New post 17 Mar 2015, 10:54
1
harDill wrote:
hi Bunuel

you wrote-
'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).'


In [highlight]statement 2
if we put value k=0 we will get 1>0. which is true. how is this a No


Your target is to find whether K can be negative or Zero or it is only positive. Remember you have to maintain the condition in statement 2

Now if K is positive, say k=1 statement 2 becomes 1+1> 1 which is true. That means by keeping k positive you can satisfy statement 2

Now if K is negative, say k= -0.5, statement 2 becomes -0.5+1> 0.125 or 0.5> 0.125 which is also true. That means by taking K= negative value you can still satisfy statement 2.

So, K can be positive and negative and zero. Therefore The answer of the question (IS K Positive) can be yes and can be no. Sot sufficient
Intern
Intern
avatar
Joined: 03 Feb 2015
Posts: 14
GMAT 1: 680 Q47 V36
GMAT 2: 720 Q49 V39
Re: D01-15  [#permalink]

Show Tags

New post 17 Mar 2015, 22:10
Bunuel wrote:
harDill wrote:
hi Bunuel

you wrote-
'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).'


In [highlight]statement 2
if we put value k=0 we will get 1>0. which is true. how is this a No


The questions asks whether k is a positive number. For (2) if k = 1 (which satisfies second statement) it IS a positive number but if k = 0 (which also satisfies second statement) it is NOT a positive number (0 is not a positive number, it's neither positive nor negative).




ok i got it now. i misunderstood the explanation the first time. thanks guys
Intern
Intern
avatar
Joined: 03 Dec 2015
Posts: 7
Re: D01-15  [#permalink]

Show Tags

New post 20 Feb 2017, 09:47
Hi all,

I successfully demonstrated that both statements taken singularly weren't sufficient to answer, however, I found myself stuck when it came to consider them together.
Being uncertain between C and E I simply guessed C..

..how can you say that the two statements are not providing any new information? They're not an identity nor equivalent, so I spent valuable seconds trying to figure out the possible scenarios when combining them.
Manager
Manager
avatar
B
Joined: 14 Jun 2016
Posts: 67
Location: India
GMAT 1: 610 Q49 V21
WE: Engineering (Manufacturing)
Reviews Badge
Re: D01-15  [#permalink]

Show Tags

New post 22 Aug 2017, 09:44
Is there any alternative way rather than just value plugging ?
Thanks in advance.
_________________

If you appreciate my post then please click +1Kudos :)

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
Re: D01-15  [#permalink]

Show Tags

New post 22 Aug 2017, 09:51
Manager
Manager
avatar
B
Joined: 11 Jun 2016
Posts: 73
Location: India
GMAT 1: 680 Q49 V35
GMAT 2: 690 Q49 V34
GPA: 3.4
Re: D01-15  [#permalink]

Show Tags

New post 16 Nov 2017, 05:43
Bunuel,

i could see that both the statements individually are insufficient. But i wasn't sure if combing them would make them sufficient .
Intern
Intern
avatar
B
Joined: 31 Dec 2017
Posts: 1
Re: D01-15  [#permalink]

Show Tags

New post 17 Jan 2018, 11:34
Hi everyone,

After demonstrating that each statement alone is not sufficient (by plugging in numbers), I proved that E is the correct answer by adding the two inequalities together:

(1) |K^3|+1>K
(2) K+1>|K^3|
Added together: |K^3|+ K+ 2 > |K^3| + K

After substracting (|K^3| + K) from both sides we get: 2 > 0, which is always true; therefore K can be any number, not only a positive one - the statements taken together are still not sufficent :-)
Current Student
User avatar
B
Joined: 28 Dec 2016
Posts: 88
Location: United States (IL)
Concentration: Marketing, General Management
Schools: Johnson '20 (M)
GMAT 1: 700 Q47 V38
Reviews Badge
Re: D01-15  [#permalink]

Show Tags

New post 31 Mar 2018, 18:11
1
Bunuel
Excellent question. Not a big deal, but small typo in your explanation:
"Statement 2 is insufficient. The logic is the same as in Statement 2."
It should probably read:
"Statement 2 is insufficient. The logic is the same as in Statement 1."
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
Re: D01-15  [#permalink]

Show Tags

New post 01 Apr 2018, 01:27
CPGguyMBA2018 wrote:
Bunuel
Excellent question. Not a big deal, but small typo in your explanation:
"Statement 2 is insufficient. The logic is the same as in Statement 2."
It should probably read:
"Statement 2 is insufficient. The logic is the same as in Statement 1."


Thank you. Edited.
_________________

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

Manager
Manager
avatar
S
Joined: 03 Apr 2015
Posts: 187
Reviews Badge CAT Tests
Re D01-15  [#permalink]

Show Tags

New post 14 Jul 2018, 11:53
the question is asking for positive number . so why are we checking for k=0
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52905
Re: D01-15  [#permalink]

Show Tags

New post 14 Jul 2018, 22:49
Intern
Intern
avatar
B
Joined: 15 Aug 2012
Posts: 42
Schools: AGSM '19
GMAT ToolKit User
Re: D01-15  [#permalink]

Show Tags

New post 16 Jul 2018, 12:00
Wanted to know if my reasoning was correct for statement 2.

Statement 1:
If K=1 then it becomes 1+1>1 This is valid
If K=-1 then it becomes 1+1>-1 This is also valid.

Since we have two options this is not sufficient.

Statement 2:

Since it says K+1>|K^3| that implies K+1>0 = K>-1. This means that K can be negative, 0 or positive. So statement 2 is sufficient.

Combining the statements give us the same information.
Intern
Intern
User avatar
B
Joined: 22 Jun 2014
Posts: 21
GMAT 1: 560 Q44 V24
GMAT 2: 660 Q49 V31
GPA: 2.5
GMAT ToolKit User Reviews Badge
Re: D01-15  [#permalink]

Show Tags

New post 06 Oct 2018, 11:02
I considered 2 different scenarios for each statements.
a) K>0
b) K<0

lets elaborate each statements in light of these scenarios.
(1) |K^3|+1>K
a) K^3 +1 >K so we have K^3-K>-1 . this statement is true for all K>0
b) -K^3 +1>K so we have K^3+K<1 . this statement is also true for all K<0
According to a&b it seems that we can not understand whether K is positive or negative.

(2) K+1>|K^3|
a) K+1>K^3 so we have K^3-K<1 . this statement can not be true for all K>0. (this statement is only true for 0<K<1)
b) K+1>-K^3 so we have K^3+K>-1 . this statement can not be true for all K<0. (This statement is only true for some -1<K<0)

As you see, neither of statements (1) or (2) are enough.
GMAT Club Bot
Re: D01-15   [#permalink] 06 Oct 2018, 11:02
Display posts from previous: Sort by

D01-15

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

Moderators: chetan2u, Bunuel



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®.