Is x a negative number?

Oldest

Best Reply

Author

Message

TAGS:

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12116

Followers: 1879

Kudos [?]: 10124 [0], given: 964

Is x a negative number? [#permalink]

06 Aug 2012, 03:11

00:00

Question Stats:

88% (01:28) correct

11% (00:12) wrong

based on 72 sessions

The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

Is x a negative number?

(1) 9x > 10x
(2) x + 3 is positive.

Practice Questions
Question: 13
Page: 276
Difficulty: 550

GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution.

We'll be glad if you participate in development of this project:
1. Please provide your solutions to the questions;
2. Please vote for the best solutions by pressing Kudos button;
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!

[Reveal] Spoiler: OA

_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!

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. NEW!!!, 11 New DS set. NEW!!!

What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Kaplan GMAT Prep Discount Codes

Knewton GMAT Discount Codes

Veritas Prep GMAT Discount Codes

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12116

Followers: 1879

Kudos [?]: 10124 [0], given: 964

Re: Is x a negative number? [#permalink]

06 Aug 2012, 03:11

SOLUTION

Is x a negative number?

(1) 9x > 10x --> rearrange: 0>10x-9x --> 0>x. Sufficient.
(2) x + 3 is positive --> x+3>0 --> x>-3. Not sufficient.

Answer: A.
_________________

Manager

Joined: 05 Jan 2011

Posts: 60

Followers: 0

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

Re: Is x a negative number? [#permalink]

06 Aug 2012, 07:45

From Statement -1 : 9 X > 10 X
Case -1 :Assuming X > 0
Dividing by X , 9>10 - Which is no true - So X <0 - Sufficient

Case-2 : X+3 >0
i.e X> -3 ....X can be any number greater than -3 -Not sufficient

Answer -

[Reveal] Spoiler:

Manager

Joined: 05 Jul 2012

Posts: 83

Location: India

Concentration: Finance, Strategy

GMAT Date: 09-30-2012

GPA: 3.08

WE: Engineering (Energy and Utilities)

Followers: 4

Kudos [?]: 6 [1] , given: 8

Re: Is x a negative number? [#permalink]

06 Aug 2012, 07:57

This post received
KUDOS

Bunuel wrote:

The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

Is x a negative number?

(1) 9x > 10x
(2) x + 3 is positive.

Practice Questions
Question: 13
Page: 276
Difficulty: 550

Now let us take it down fat and very fast, cos this is a very wussy question where we have to save time for the other tough problems we should not take more than 10 seconds to solve it .
9x>10x implies x < 0 9 (Awesome )
x+3 > 0 implies x > -3 ( not good )
Answer is A

Senior Manager

Joined: 15 Jun 2010

Posts: 362

Schools: IE'14, ISB'14, Kellogg'15

WE 1: 7 Yrs in Automobile (Commercial Vehicle industry)

Followers: 4

Kudos [?]: 84 [0], given: 50

Re: Is x a negative number? [#permalink]

06 Aug 2012, 08:35

IMO A

st 1: sufficient x is -ve
st 2: not sufficient x can be +ve, -ve or zero
_________________

Regards
SD
-----------------------------
Press Kudos if you like my post.
Debrief 610-540-580-710(Long Journey): from-600-540-580-710-finally-achieved-in-4th-attempt-142456.html

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12116

Followers: 1879

Kudos [?]: 10124 [0], given: 964

Re: Is x a negative number? [#permalink]

10 Aug 2012, 04:58

SOLUTION

Is x a negative number?

(1) 9x > 10x --> rearrange: 0>10x-9x --> 0>x. Sufficient.
(2) x + 3 is positive --> x+3>0 --> x>-3. Not sufficient.

Answer: A.
_________________

SVP

Joined: 01 Sep 2010

Posts: 1797

Followers: 64

Kudos [?]: 652 [0], given: 478

Is x a negative number? [#permalink]

22 Sep 2012, 17:08

Is x a negative number?

(1) 9x > 10x
(2) x + 3 is positive.

i would like to know if my process is correct

1) 9x - 10x >0 ----> x (9-10) > 0 -----> x > 0 suff

2) x + 3 = pos x can be a positive value 4 + 3 = 7 or negative -1 + 3 = 2 always positive insuff

In particular I wish to know about the first stat.

Thanks
_________________

KUDOS is the good manner to help the entire community.

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12116

Followers: 1879

Kudos [?]: 10124 [0], given: 964

Re: Is x a negative number? [#permalink]

22 Sep 2012, 22:52

carcass wrote:

Merging similar topics. Please refer to the solutions above and ask if anything remains unclear.
_________________

Director

Status: Final Lap Up!!!

Affiliations: NYK Line

Joined: 21 Sep 2012

Posts: 981

Location: India

Schools: McCombs '16, Tulane '16, Jones '16, Cox '16, AGSM '15, Neeley '16

GMAT 1: 410 Q35 V11
GMAT 2: 530 Q44 V20
GMAT 3: 630 Q45 V31

GPA: 3.2

WE: Engineering (Transportation)

Followers: 15

Kudos [?]: 105 [0], given: 58

Re: Is x a negative number? [#permalink]

22 Sep 2012, 23:24

9x>10X only if x is -ve it cant be greater when x is + ve
hence 1 is sufficient
but statement 2 is insufficient as x can hav the value as 0 and any + ve num
zero is neither +ve nor - ve
hence insufficient
A is the answer

SVP

Joined: 01 Sep 2010

Posts: 1797

Followers: 64

Kudos [?]: 652 [0], given: 478

Re: Is x a negative number? [#permalink]

23 Sep 2012, 05:00

Bunuel wrote:

SOLUTION

Is x a negative number?

(1) 9x > 10x --> rearrange: 0>10x-9x --> 0>x. Sufficient.
(2) x + 3 is positive --> x+3>0 --> x>-3. Not sufficient.

Answer: A.

Hi Bunuel.

What is unclear for me is not the probelm by itself (I picked the right answer but the first statement

1) 0 > of something then X must be negative. The answer is definitevely YES.

Instead, I have obtained YES too but X is definetevely positive. In this scenario is the same, the most imprtant thing is to have a definitive answer, or is wrong thinking in this way??

Thanks
_________________

KUDOS is the good manner to help the entire community.

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12116

Followers: 1879

Kudos [?]: 10124 [0], given: 964

Re: Is x a negative number? [#permalink]

24 Sep 2012, 04:04

carcass wrote:

Bunuel wrote:

SOLUTION

Is x a negative number?

(1) 9x > 10x --> rearrange: 0>10x-9x --> 0>x. Sufficient.
(2) x + 3 is positive --> x+3>0 --> x>-3. Not sufficient.

Answer: A.

Well, from (1) we have that x<0, so x is negative not positive.

As for your question: in a Yes/No Data Sufficiency question, statement(s) is sufficient if the answer is “always yes” or “always no” while a statement(s) is insufficient if the answer is "sometimes yes" and "sometimes no".

Hope it's clear.
_________________

Re: Is x a negative number? [#permalink] 24 Sep 2012, 04:04

		Similar topics	Author	Replies	Last post
Similar Topics:	1	Is X a negative number? statement 1: x^2 is a positive	bandit	7	15 Mar 2009, 09:58
	1	Is x a negative number? (1) x2 is a positive number. (2) x	prinits	12	31 May 2009, 07:23
		Is x a negative number? (1) x^2 is a positive number. (2) x	hogann	6	10 Oct 2009, 15:01
	2	Is x negative?	gi	5	21 Dec 2009, 13:01
		if x and y are negative numbers, is x<y	yezz	1	15 May 2013, 09:09

Is x a negative number?

Main navigation

GMAT Resources

Partners

MBA Resources

GMAT ® is a registered trademark of the Graduate Management Admission Council ® (GMAC ®). GMAT Club's website has not been reviewed or endorsed by GMAC.

GMAT Courses

Admissions Consulting

Is x a negative number?

Is x a negative number?

Main navigation

GMAT Resources

Partners

MBA Resources