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

 It is currently 07 Feb 2016, 07:22

### 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

# If x is negative, is x < -3 ?

Author Message
TAGS:
Intern
Joined: 30 Sep 2010
Posts: 19
Followers: 0

Kudos [?]: 74 [4] , given: 1

If x is negative, is x < -3 ? [#permalink]  02 Jan 2011, 07:47
4
KUDOS
18
This post was
BOOKMARKED
00:00

Difficulty:

65% (hard)

Question Stats:

50% (02:11) correct 50% (01:15) wrong based on 741 sessions
If x is negative, is x < –3 ?

(1) x^2 > 9
(2) x^3 < –9
[Reveal] Spoiler: OA

Last edited by Engr2012 on 12 Sep 2015, 08:44, edited 2 times in total.
Renamed the topic and edited the question.
Math Expert
Joined: 02 Sep 2009
Posts: 31232
Followers: 5344

Kudos [?]: 62091 [2] , given: 9440

Re: If x is negative, is x < -3 ? [#permalink]  02 Jan 2011, 07:57
2
KUDOS
Expert's post
5
This post was
BOOKMARKED
If x is negative, is x < –3 ?

(1) x^2 > 9 --> $$x<-3$$ or $$x>3$$ as given that $$x<0$$ then we have that $$x<-3$$. Sufficient.

(2) x^3 < –9 --> if $$x=-3$$ ($$x^3=-27<-9$$) then the answer will be NO (as $$x$$ equals to -3 and is not less than -3) but if $$x=-4$$ ($$x^3=-64<-9$$) then the answer will be YES. Not sufficient.

_________________
Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2022
Followers: 149

Kudos [?]: 1358 [1] , given: 376

Re: If x is negative, is x < -3 ? [#permalink]  24 Feb 2011, 04:11
1
KUDOS
1.
$$x^2>9$$
$$|x|>3$$
$$x>3 \hspace{3} or \hspace{3} x<-3$$
We know that x is -ve.
Thus;
$$x<-3$$
Sufficient.

2.
$$x^3<-9$$
$$x^3$$ can be -27 making x=-3 or $$x^3$$ can be -64 making x=-4[/m]
We can't conclude that x is definitely smaller than -3.
Not Sufficient.

Ans:"A"
_________________
Manager
Joined: 25 Jul 2012
Posts: 78
Location: United States
Followers: 0

Kudos [?]: 60 [0], given: 137

Re: If x is negative, is x < -3 ? [#permalink]  09 Mar 2013, 10:41
I'm not seeing something in testing out statement 2.

Would someone be able to illustrate on a number line when testing out x=-3 and x=-4 only -64 <-3 and not -27?

And if you have a similar problem, please post.
_________________

If my post has contributed to your learning or teaching in any way, feel free to hit the kudos button ^_^

Math Expert
Joined: 02 Sep 2009
Posts: 31232
Followers: 5344

Kudos [?]: 62091 [0], given: 9440

Re: If x is negative, is x < -3 ? [#permalink]  10 Mar 2013, 05:07
Expert's post
DelSingh wrote:
I'm not seeing something in testing out statement 2.

Would someone be able to illustrate on a number line when testing out x=-3 and x=-4 only -64 <-3 and not -27?

And if you have a similar problem, please post.

Not sure I understand what you mean there. Can you please elaborate? Thank you.

Anyway both -64 and -27 are less than -3, since both are negative and further from 0 than -3 is.
_________________
Manager
Joined: 25 Jul 2012
Posts: 78
Location: United States
Followers: 0

Kudos [?]: 60 [0], given: 137

Re: If x is negative, is x < -3 ? [#permalink]  10 Mar 2013, 11:03
Bunuel wrote:
DelSingh wrote:
I'm not seeing something in testing out statement 2.

Would someone be able to illustrate on a number line when testing out x=-3 and x=-4 only -64 <-3 and not -27?

And if you have a similar problem, please post.

Not sure I understand what you mean there. Can you please elaborate? Thank you.

Anyway both -64 and -27 are less than -3, since both are negative and further from 0 than -3 is.

Hopefully this will show what I am doing wrong in statement two:

I had sufficient for statement 2 but that was wrong
_________________

If my post has contributed to your learning or teaching in any way, feel free to hit the kudos button ^_^

Intern
Joined: 09 Mar 2013
Posts: 9
Concentration: Accounting
GMAT Date: 05-01-2013
GPA: 3.57
Followers: 0

Kudos [?]: 2 [1] , given: 2

Re: If x is negative, is x < -3 ? [#permalink]  10 Mar 2013, 15:02
1
KUDOS
they are asking is x<-3, not if x^3<-3. -27 and -64 are the values of x^3. so x=-3 and x=-4. negative 3 isn't less than negative 3, so answer is no. negative 4 is less than negative 3, so answer is yes. insufficient.
Math Expert
Joined: 02 Sep 2009
Posts: 31232
Followers: 5344

Kudos [?]: 62091 [1] , given: 9440

Re: If x is negative, is x < -3 ? [#permalink]  10 Mar 2013, 21:49
1
KUDOS
Expert's post
DelSingh wrote:
Bunuel wrote:
DelSingh wrote:
I'm not seeing something in testing out statement 2.

Would someone be able to illustrate on a number line when testing out x=-3 and x=-4 only -64 <-3 and not -27?

And if you have a similar problem, please post.

Not sure I understand what you mean there. Can you please elaborate? Thank you.

Anyway both -64 and -27 are less than -3, since both are negative and further from 0 than -3 is.

Hopefully this will show what I am doing wrong in statement two:

I had sufficient for statement 2 but that was wrong

x = -3 and x = -4 satisfy the second statement: (-3)^3 < -9 and (-4)^3 < -9.

Now, if x = -4 we have an YES answer because -4 < -3;
But if x = -3 we have a NO answer because -3 = -3 (x equals to -3 and is not less than -3).

Hope it's clear.
_________________
Manager
Joined: 25 Jul 2012
Posts: 78
Location: United States
Followers: 0

Kudos [?]: 60 [0], given: 137

Re: If x is negative, is x < -3 ? [#permalink]  11 Mar 2013, 08:49
Now I see, I just got lost in translation and calculation, and didn't remember the actual question stem. Thank you both
_________________

If my post has contributed to your learning or teaching in any way, feel free to hit the kudos button ^_^

Intern
Joined: 07 Feb 2013
Posts: 13
GMAT 1: 650 Q48 V32
GMAT 2: 730 Q49 V41
WE: Engineering (Other)
Followers: 0

Kudos [?]: 15 [1] , given: 9

Re: If x is negative, is x < -3 ? [#permalink]  20 Jun 2013, 13:37
1
KUDOS
Statement 2 : X^3<-9
=> We know (-2)^3 = -8 and (-3)^3= -27
=> it isnt given in the q that x has to be an integer
=> x can be any decimal slightly less than -2.0 ie. -2.5^3 (-15) and thus give an answer NO
& x can be any number <-3 (=>x^3 <-27)and give an answer YES.
Thus, insufficient
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 8161
Followers: 416

Kudos [?]: 111 [0], given: 0

Re: If x is negative, is x < -3 ? [#permalink]  12 Aug 2014, 09:12
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 8161
Followers: 416

Kudos [?]: 111 [0], given: 0

Re: If x is negative, is x < -3 ? [#permalink]  29 Aug 2015, 00:55
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Manager
Joined: 10 Dec 2012
Posts: 52
Followers: 0

Kudos [?]: 4 [0], given: 36

Re: If x is negative, is x < -3 ? [#permalink]  12 Sep 2015, 08:04
If x is negative, is x< -3?

1) x^2> 9

2) x^3 > -9
Manager
Joined: 10 Dec 2012
Posts: 52
Followers: 0

Kudos [?]: 4 [0], given: 36

Re: If x is negative, is x < -3 ? [#permalink]  12 Sep 2015, 08:16

I'm trying to remove this question but i can't see the option to do so...as i have found the same question that i couldn't find earlier..
Thank you.
Math Forum Moderator
Joined: 20 Mar 2014
Posts: 2205
GMAT 1: 650 Q49 V30
GMAT 2: 690 Q49 V34
GMAT 3: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Followers: 67

Kudos [?]: 829 [0], given: 612

Re: If x is negative, is x < -3 ? [#permalink]  12 Sep 2015, 08:25
jaspreets wrote:

I'm trying to remove this question but i can't see the option to do so...as i have found the same question that i couldn't find earlier..
Thank you.

Thanks. Topics merged. Refer above for the solution.
_________________

Thursday with Ron updated list as of July 1st, 2015: http://gmatclub.com/forum/consolidated-thursday-with-ron-list-for-all-the-sections-201006.html#p1544515
Debrief, 650 to 750: http://gmatclub.com/forum/650-to-750-a-10-month-journey-to-the-score-203190.html

Manager
Joined: 10 Dec 2012
Posts: 52
Followers: 0

Kudos [?]: 4 [0], given: 36

Re: If x is negative, is x < -3 ? [#permalink]  12 Sep 2015, 08:40
Hi Engr2012

Please edit the headline as the minus sign is missing thus the question doesn't appear in search box..
I has to be

if x is negative, is x < - 3 ?

Thank you.
Senior Manager
Joined: 29 Oct 2013
Posts: 275
Concentration: Finance
Schools: Johnson
GMAT 1: 750 Q V
GPA: 3.7
WE: Corporate Finance (Retail Banking)
Followers: 12

Kudos [?]: 265 [1] , given: 179

If x is negative, is x < -3 ? [#permalink]  02 Dec 2015, 22:31
1
KUDOS
St1) Quite obviously SUFF
St2) x^3<-9. First of all x has to be negative as cube root of a negative number will be negative. Now lets take cube root of both sides:
x<- (~2.1) ...[we know than cube root of -8 is -2, so cube root of of -9 will be just slightly smaller than -2]
So our ballpark estimate is that x lies to the left of -2.1 we don't know if it will lie to the left of -3. INSUF

Alternatively-

Stem: If x is negative, is x < -3 ?
In other words,
i) is x^2>9? (Inequality sign will flip)
ii) is x^3<-27? (Ineqality sign doesnt change)
ii) is x^4> 81? (Inequality sign will flip)
etc
etc
.
.
.
st1) Straight away yes from i)...SUF
St2) only tells us x^3 is less than -9 so x^3 could be less than -27 or not. INSUF

Ans: A
_________________

Please consider giving 'kudos' if you like my post and want to thank

If x is negative, is x < -3 ?   [#permalink] 02 Dec 2015, 22:31
Similar topics Replies Last post
Similar
Topics:
If x is negative, is x< -3? 0 12 Sep 2015, 08:16
2 Is x negative? (1) x^2 + 25 = 89 (2) x^3 < x 4 27 Aug 2015, 00:30
if x and y are negative numbers, is x<y 1 15 May 2013, 08:09
2 If x is negative, is x <-3? (1) x^2 > 9 (2) x^3 < 9 18 May 2011, 23:17
6 If x is negative, is x < –3 ? (1) x^2 > 9 (2) x^3 < –9 4 27 Feb 2010, 23:09
Display posts from previous: Sort by