Is a/b < 0? : GMAT Data Sufficiency (DS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 17:49

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Is a/b < 0?

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

### Hide Tags

Senior Manager
Joined: 29 Jan 2011
Posts: 367
Followers: 0

Kudos [?]: 201 [0], given: 87

Is a/b < 0? [#permalink]

### Show Tags

19 Jun 2011, 15:32
2
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

71% (01:38) correct 29% (01:54) wrong based on 237 sessions

### HideShow timer Statistics

Is a/b < 0?

(1) a^2/b^3 > 0

(2) ab^4 < 0
[Reveal] Spoiler: OA

Last edited by siddhans on 20 Jun 2011, 21:30, edited 1 time in total.
SVP
Joined: 16 Nov 2010
Posts: 1672
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 33

Kudos [?]: 514 [1] , given: 36

Re: MGMAT DS [#permalink]

### Show Tags

19 Jun 2011, 17:20
1
KUDOS
The answer is C.

(1) says that b > 0, since a^2 is always positive, so we don't know the sign of a. Insufficient.

(2) says a is negative as b^4 is always positive, so we don't know the sign of b. Insufficient.

(1) + (2) Sufficient as we know signs of both a and b.

_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Intern
Joined: 18 Mar 2013
Posts: 5
Followers: 0

Kudos [?]: 2 [0], given: 45

Positives and Negatives [#permalink]

### Show Tags

10 May 2013, 12:09
Is [a]/[b] < 0?

(1) a[square_root]/[b3]> 0
(2) ab4 < 0
Manager
Status: Pushing Hard
Affiliations: GNGO2, SSCRB
Joined: 30 Sep 2012
Posts: 89
Location: India
Concentration: Finance, Entrepreneurship
GPA: 3.33
WE: Analyst (Health Care)
Followers: 1

Kudos [?]: 83 [1] , given: 11

Re: Positives and Negatives [#permalink]

### Show Tags

10 May 2013, 20:21
1
KUDOS
The question basically asks ....

IS $$lal$$ < 0 ??

or a < 0 & a > 0 ......Does the value of a >0 & a <0 .....

Statement : 1 says ...... $$\sqrt{{a}} / l{b^3}l$$ > 0

or $$\sqrt{{a}}$$> 0

or a > 0 ... Clearly Insufficient as it doesn't tell us if a< 0 also......Therefore, Insufficient.

Statement :: 2 ... Similar to statement it just tells us one part ... i.e;

as Given ... $$ab^4$$ < 0 ... or a <0 .... Clearly, Insufficient.

1+2 ...... gives us that a<0 & a > 0 ..... Therefore, Sufficient.......

Hence, C ................. Hope it Helps !!
_________________

If you don’t make mistakes, you’re not working hard. And Now that’s a Huge mistake.

Math Expert
Joined: 02 Sep 2009
Posts: 36540
Followers: 7072

Kudos [?]: 93037 [0], given: 10541

Re: Positives and Negatives [#permalink]

### Show Tags

11 May 2013, 02:55
samheeta wrote:
Is [a]/[b] < 0?

(1) a[square_root]/[b3]> 0
(2) ab4 < 0

Merging topics.

_________________
Intern
Joined: 28 May 2013
Posts: 13
Followers: 0

Kudos [?]: 26 [0], given: 2

Re: Is a/b < 0? (1)a^2/b^3 > 0 (2) ab^4 < 0 [#permalink]

### Show Tags

08 Oct 2013, 07:35
Hi Bunuel/All ,

Why are we not considering a & b to be fractions?

Regards
Akshay
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7119
Location: Pune, India
Followers: 2131

Kudos [?]: 13631 [0], given: 222

Re: Is a/b < 0? (1)a^2/b^3 > 0 (2) ab^4 < 0 [#permalink]

### Show Tags

08 Oct 2013, 22:51
AkshayChittoria wrote:
Hi Bunuel/All ,

Why are we not considering a & b to be fractions?

Regards
Akshay

Responding to a pm:

a and b could be fractions. We are not assuming that they must be integers. We are only talking about their sign.

(1)a^2/b^3 > 0

It doesn't matter whether a and b are fractions or integers, a^2 will be positive. So b must be positive since positive/b^3 is positive. But we don't know whether a is positive or negative. Can't say about the sign of a/b

(2) ab^4 < 0

b^4 must be positive. So a must be negative because a/positive is negative. Can't say about the sign of a/b

Both together, b is positive and a is negative so a/b must be negative. Sufficient.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Intern
Joined: 28 May 2013
Posts: 13
Followers: 0

Kudos [?]: 26 [0], given: 2

Re: Is a/b < 0? [#permalink]

### Show Tags

09 Oct 2013, 00:27
Thanks Karishma . I think sometimes it is better not to think too much and skip some possible scenarios .
Manager
Joined: 24 Apr 2013
Posts: 71
Location: United States
Followers: 0

Kudos [?]: 12 [0], given: 23

Re: Is a/b < 0? [#permalink]

### Show Tags

17 Oct 2013, 01:26
Clumsy mistake.
I read st 2 as (ab)^4 <0
_________________

Struggling: make or break attempt

Senior Manager
Status: Exam scheduled!!
Joined: 05 Sep 2016
Posts: 411
Location: United States (WI)
Concentration: Marketing, Technology
WE: Other (Law)
Followers: 3

Kudos [?]: 13 [0], given: 241

Re: Is a/b < 0? [#permalink]

### Show Tags

23 Sep 2016, 09:26
C is correct. Here's why:

(1) a^2/b^3 > 0

From this we know that b < 0, but we don't know whether a<0 or a>0, thus INSUFFICIENT

(2) ab^4 < 0

From this we know a < 0, but we don't know whether b>0 or b<0, thus INSUFFICIENT

(1) + (2) - We know a<0 and b>0, therefore we know a/b<0 SUFFICIENT
Re: Is a/b < 0?   [#permalink] 23 Sep 2016, 09:26
Similar topics Replies Last post
Similar
Topics:
If ab # 0, is a/b < 1? 2 05 Dec 2016, 01:59
Is ab < 0 ? (1) a = b - 6 (2) b < 0 7 28 Oct 2015, 06:18
2 If ab − bc^2 < 0, is a < 0? 2 13 Jan 2014, 04:25
6 Is 0< a/b < 1? 7 13 Nov 2013, 15:17
6 If 0 < ab < ac, is a negative? 4 15 Nov 2012, 11:08
Display posts from previous: Sort by

# Is a/b < 0?

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

 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®.