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

It is currently 10 Dec 2018, 03:00

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
  • Free lesson on number properties

     December 10, 2018

     December 10, 2018

     10:00 PM PST

     11:00 PM PST

    Practice the one most important Quant section - Integer properties, and rapidly improve your skills.
  • Free GMAT Prep Hour

     December 11, 2018

     December 11, 2018

     09:00 PM EST

     10:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. December 11 at 9 PM EST.

Is d negative?

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

Hide Tags

Intern
Intern
avatar
Joined: 05 Mar 2014
Posts: 5
Is d negative?  [#permalink]

Show Tags

New post 10 Apr 2014, 06:10
1
6
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

62% (01:49) correct 38% (01:48) wrong based on 319 sessions

HideShow timer Statistics

Is d negative?

(1) e + d = -12

(2) e – d < -12

Spoiler: :: Answer and explanation
(1) e+d = -12
=> d = -12-e, however as we don't know anything about e, it could be 1 (thus d=-13) or -13 (thus d=1) = insufficient

(2) e-d < -12
=> d > 12+e, again e can be anything => insufficient

(1) + (2)
from 1: e=-12-d
from 2: e<-12+d
together: -12-d < -12+d => -d < +d

this is only true if d is positive.

Therefore: Answer is C

However that's not the text books answer explanation, so I thought I'd ask you guys for your opinion and if there are any flaws in the answer that I overlooked.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51067
Re: Is d negative?  [#permalink]

Show Tags

New post 10 Apr 2014, 06:17
1
3
jumli wrote:
Is d negative?

(1) e + d = -12

(2) e – d < -12

Spoiler: :: Answer and explanation
(1) e+d = -12
=> d = -12-e, however as we don't know anything about e, it could be 1 (thus d=-13) or -13 (thus d=1) = insufficient

(2) e-d < -12
=> d > 12+e, again e can be anything => insufficient

(1) + (2)
from 1: e=-12-d
from 2: e<-12+d
together: -12-d < -12+d => -d < +d

this is only true if d is positive.

Therefore: Answer is C

However that's not the text books answer explanation, so I thought I'd ask you guys for your opinion and if there are any flaws in the answer that I overlooked.


Is d negative?

(1) e + d = -12. d can be negative as well as non-negative. For example, consider d=0 and e=-12 and d=-1 and e=-11. Not sufficient.

(2) e – d < -12. d can be negative as well as non-negative. For example, consider d=0 and e=-13 and d=-1 and e=-14. Not sufficient.

(1)+(2) From (1) we have that e = -12 - d, thus from (2) (-12 - d) - d < -12 --> -2d<0 --> d>0. 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

CEO
CEO
User avatar
P
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2709
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: Is d negative?  [#permalink]

Show Tags

New post 02 Jul 2015, 09:31
jumli wrote:
Is d negative?

(1) e + d = -12

(2) e – d < -12



Question : Is d < 0?

Statement 1:e + d = -12

@e=2, d=-14 We observe that d may be negative
@e=-14, d=2 We observe that d may be Positive

NOT SUFFICIENT

Statement 2: e - d < -12

@e=-15, d=1, e-d = -16 i.e. Less than -12 We observe that d may be Positive
@e=-15, d=-2, e-d = -13 i.e. Less than -12 We observe that d may be Negative

NOT SUFFICIENT

Combining the Two statements

e = -12-d
and e - d < -12
i.e. (-12-d)- d < -12
i.e. (-12-2d) < -12
i.e. 2d > 0
i.e. d is positive

SUFFICIENT

Answer: option C
_________________

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

Manager
Manager
User avatar
P
Joined: 13 Jun 2012
Posts: 201
Location: United States
WE: Supply Chain Management (Computer Hardware)
GMAT ToolKit User CAT Tests
Re: Is d negative?  [#permalink]

Show Tags

New post 05 May 2016, 15:03
(1) e + d = -12
(2) e - d < -12

1 and 2 alone are not possible.

Together e - d<e + d since -12 = e + d
0<2d or 0<d is positive . Ans C
Intern
Intern
avatar
Joined: 25 Aug 2015
Posts: 5
Is d negative?  [#permalink]

Show Tags

New post 05 May 2016, 16:54
(1) is not enough

(2) e+12<d is not enough

(1)&(2) we know from (1) that e+12+d=0 and we know from (2) e+12<d. Therefore, we can say that d+d>0=> d>0

In my opinion, the answer is c

I may have simplified the question too much, but this is how I solved it
Intern
Intern
avatar
B
Joined: 12 May 2017
Posts: 10
Location: United States (CA)
Concentration: Real Estate, Nonprofit
GPA: 3.85
Re: Is d negative?  [#permalink]

Show Tags

New post 16 May 2017, 15:14
the problem is not hard, and since I have completed all set of quantitative quiz from one of members in the forum, i can solve this problem easily.
Intern
Intern
User avatar
B
Joined: 15 May 2017
Posts: 3
Re: Is d negative?  [#permalink]

Show Tags

New post 16 May 2017, 22:25
Is d negative?
(1) e + d = -12
(2) e – d < -12

Ans:
From (1), e + d = -12, we can't tell if d is +ve or -ve ( if positive , e is -ve and more in magnitude than d by 12)
From (2), e – d < -12 too, we can't tell.
Hence , we put (1) into (2),
=> Putting e= -12 - d
=> (-12-d) - d < -12
=> -12 - 2d < -12
=> d > 0

Hence, statements 1 and 2 together are sufficient to answer the question but not alone.

Good day :)
Director
Director
User avatar
D
Joined: 04 Dec 2015
Posts: 725
Location: India
Concentration: Technology, Strategy
Schools: ISB '19, IIMA , IIMB, XLRI
WE: Information Technology (Consulting)
GMAT ToolKit User
Re: Is d negative?  [#permalink]

Show Tags

New post 22 Jul 2017, 12:18
jumli wrote:
Is d negative?

(1) e + d = -12

(2) e – d < -12


Is \(d\) negative? (Its a YES/NO Question.)

(1) \(e + d = -12\)

\(e = -12 - d\) -------- (i)

We cannot find value of \(e\) or \(d\). Hence I is Not Sufficient.

(2) \(e – d < -12\)

We cannot find value of \(e\) or \(d\). Hence II is Not Sufficient.

Combining (1) and (2)

Substituting value of \(e\) from (i) in (2), we get;

\(-12 -d -d < -12\)

\(-2d < 0\)

\(2d > 0\)

\(d > 0\)

Therefore \(d\) is positive.

Combining (1) and (2), we get the Answer to question is \(d\) negative is NO.

Answer (C)...
Intern
Intern
avatar
B
Joined: 02 Sep 2017
Posts: 24
Is d negative?  [#permalink]

Show Tags

New post Updated on: 26 May 2018, 03:56
Is d negative?

(1) e + d = -12
(2) e – d < -12

Originally posted by shringi87 on 26 May 2018, 02:34.
Last edited by abhimahna on 26 May 2018, 03:56, edited 1 time in total.
Edited the question
Manager
Manager
avatar
B
Joined: 06 May 2018
Posts: 59
Re: Is d negative?  [#permalink]

Show Tags

New post 26 May 2018, 03:14
Both statements alone are not sufficient. If you plug in statement one in statement you get -2d<0. Therefore d is >0. Answer c is correct.
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7096
Re: Is d negative?  [#permalink]

Show Tags

New post 26 May 2018, 03:43
shringi87 wrote:
Is d negative?

(1) e + d = -12
(2) e – d < -12



1) e+d=-12
If e <-12, d will be >0....and NO
If e>-12, d Will be negative...YES
Insufficient

2) e-d<-12
d>e+12..
If e=-12, d>0
If e=-15, d can be > or <0..
Insufficient

Combined..
From 1) e=-d-12..
So -d-12-d<-12.......-2d<0....2d>0..
Sufficient as and is NO
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51067
Re: Is d negative?  [#permalink]

Show Tags

New post 26 May 2018, 04:01
CEO
CEO
User avatar
D
Joined: 11 Sep 2015
Posts: 3222
Location: Canada
Re: Is d negative?  [#permalink]

Show Tags

New post 26 May 2018, 07:32
Top Contributor
jumli wrote:
Is d negative?

(1) e + d = -12

(2) e – d < -12


Target question: Is d negative?

Statement 1: e + d = -12
Let's TEST some values.
There are several values of e and d that satisfy statement 1. Here are two:
Case a: d = -6 and e = -6. Notice that e + d = (-6) + (-6) = -12. In this case, the answer to the target question is YES, d IS negative
Case b: d = 1 and e = -13. Notice that e + d = (-13) + 1 = -12. In this case, the answer to the target question is NO, d is NOT negative
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: e – d < -12
There are several values of e and d that satisfy statement 2. Here are two:
Case a: d = 13 and e = 0. Notice that e - d = 0 - 13 = -13, and -13 < -12. In this case, the answer to the target question is NO, d is NOT negative
Case b: d = -5 and e = -20. Notice that e - d = -20 - (-5) = -15, and -15 < -12. In this case, the answer to the target question is YES, d IS negative
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that e + d = -12
Statement 2 tells us that e – d < -12
If e + d = -12, then e = -12 - d
Now take e – d < -12 and replace e with -12 - d to get: (-12 - d) – d < -12
Simplify: -12 - 2d < -12
Add 12 to both sides: -2d < 0
Divide both sides by -2 to get: d > 0 [since we divided by a NEGATIVE value, we REVERSED the direction of the inequality symbol]
So, the answer to the target question is NO, d is NOT negative
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

RELATED VIDEO FROM OUR COURSE

_________________

Test confidently with gmatprepnow.com
Image

Director
Director
avatar
P
Joined: 02 Oct 2017
Posts: 724
Re: Is d negative?  [#permalink]

Show Tags

New post 24 Jun 2018, 08:05
Both I and II statements are not giving answers...

Only after combining two
Putting equation 1 in 2
We get
-2d<0

I.e. d>0
So C is answer

Give kudos if it helps

Posted from my mobile device
_________________

Give kudos if you like the post

Director
Director
User avatar
D
Joined: 11 Feb 2015
Posts: 608
Premium Member CAT Tests
Re: Is d negative?  [#permalink]

Show Tags

New post 27 Jun 2018, 10:27
This is a Yes/No question.

Since number testing is quick, it is advisable to to quickly test some scenarios:-

Attachment:
2018-06-27_23-48-51.jpg
2018-06-27_23-48-51.jpg [ 184.98 KiB | Viewed 587 times ]


We have seen above that Statement 1 & 2 are not sufficient by own. We are down to C vs E

Hence we combine the two statements. Scenario 1 satisfies the conditions but Scenario 2 does not satisfy the conditions. We need to analyse this further. We need a concrete proof before we conclude either way.

Since it is given that e + d = -12; therefore e = -12 - d
Statement (2) states that e – d < -12 therefore substitute e = (-12 - d) to get: (-12 - d) – d < -12
Simplification implies that d > 0 or we get a definite "No" to the question "Is d negative?". Hence for both the equations to hold together d have to be positive therefore (C) is sufficient.
_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"

Manager
Manager
avatar
S
Joined: 07 Feb 2017
Posts: 188
Re: Is d negative?  [#permalink]

Show Tags

New post 27 Jun 2018, 10:38
(1) e=1; d=-13
e=-13; d=1
Insufficient

(2) e=-13; d=1
e=-14; d=-1
Insufficient

(1) and (2)
-12-d-d < -12
-2d < 0
d>0
Sufficient
Answer C
GMAT Club Bot
Re: Is d negative? &nbs [#permalink] 27 Jun 2018, 10:38
Display posts from previous: Sort by

Is d negative?

  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®.