It is currently 21 Nov 2017, 05:38

### 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

# N is an integer. Is N negative ?

Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 10 Apr 2012
Posts: 277

Kudos [?]: 1182 [0], given: 325

Location: United States
Concentration: Technology, Other
GPA: 2.44
WE: Project Management (Telecommunications)
N is an integer. Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 15:49
2
This post was
BOOKMARKED
00:00

Difficulty:

75% (hard)

Question Stats:

34% (00:46) correct 66% (00:32) wrong based on 133 sessions

### HideShow timer Statistics

N is an integer. Is N negative ?

(1) |N| = -N
(2) N^4 = N^2
[Reveal] Spoiler: OA

Kudos [?]: 1182 [0], given: 325

VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1120

Kudos [?]: 2375 [3], given: 219

Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 15:56
3
KUDOS
N is an integer . Is N negative ?

A) $$|N|= -N$$
That is true if $$N\leq{0}$$
Not sufficient to say that is negative (could be 0).

B) $$N^4=N^2$$
$$N^4-N^2=0$$ $$N^2(N^2-1)=0$$ so N could be 0,1 or -1.
Not sufficient

1+2) N could still be 0 or -1. Not sufficient
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Kudos [?]: 2375 [3], given: 219

Senior Manager
Joined: 13 May 2013
Posts: 460

Kudos [?]: 202 [0], given: 134

Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 17:51
This may be a silly question but could you go over #1 in a bit more depth?

Thanks!

Zarrolou wrote:
N is an integer . Is N negative ?

A) $$|N|= -N$$
That is true if $$N\leq{0}$$
Not sufficient to say that is negative (could be 0).

B) $$N^4=N^2$$
$$N^4-N^2=0$$ $$N^2(N^2-1)=0$$ so N could be 0,1 or -1.
Not sufficient

1+2) N could still be 0 or -1. Not sufficient

Kudos [?]: 202 [0], given: 134

VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1120

Kudos [?]: 2375 [1], given: 219

Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 17:56
1
KUDOS
WholeLottaLove wrote:
This may be a silly question but could you go over #1 in a bit more depth?

Thanks!

$$|N|= -N$$

If $$N>0$$ then $$N=-N$$ or $$N=0$$ but since 0 is not in the interval $$>0$$, this is not a valid solution.

If $$N\leq{0}$$ then $$-N=-N$$ and is always true (-n always equal -n).

So the original $$|N|= -N$$ tells us that $$N\leq{0}$$.

Hope it's clear
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Kudos [?]: 2375 [1], given: 219

Math Expert
Joined: 02 Sep 2009
Posts: 42280

Kudos [?]: 132894 [1], given: 12391

Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 17:59
1
KUDOS
Expert's post
WholeLottaLove wrote:
This may be a silly question but could you go over #1 in a bit more depth?

Thanks!

Zarrolou wrote:
N is an integer . Is N negative ?

A) $$|N|= -N$$
That is true if $$N\leq{0}$$
Not sufficient to say that is negative (could be 0).

B) $$N^4=N^2$$
$$N^4-N^2=0$$ $$N^2(N^2-1)=0$$ so N could be 0,1 or -1.
Not sufficient

1+2) N could still be 0 or -1. Not sufficient

This is basics of absolute value:

$$|x|=-x$$ when $$x\leq{0}$$.
$$|x|=x$$ when $$x\geq{0}$$.
_________________

Kudos [?]: 132894 [1], given: 12391

Senior Manager
Joined: 13 May 2013
Posts: 460

Kudos [?]: 202 [0], given: 134

Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 18:32
Wait, why does N = 0?

Zarrolou wrote:
WholeLottaLove wrote:
This may be a silly question but could you go over #1 in a bit more depth?

Thanks!

$$|N|= -N$$

If $$N>0$$ then $$N=-N$$ or $$N=0$$ but since 0 is not in the interval $$>0$$, this is not a valid solution.

If $$N\leq{0}$$ then $$-N=-N$$ and is always true (-n always equal -n).

So the original $$|N|= -N$$ tells us that $$N\leq{0}$$.

Hope it's clear

Kudos [?]: 202 [0], given: 134

VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1120

Kudos [?]: 2375 [1], given: 219

Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 18:33
1
KUDOS
WholeLottaLove wrote:
Wait, why does N = 0?

If $$N>0$$ then $$N=-N$$ or $$2N=0$$ or $$N=0$$ but since 0 is not in the interval $$>0$$, this is not a valid solution.
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Kudos [?]: 2375 [1], given: 219

Senior Manager
Joined: 13 May 2013
Posts: 460

Kudos [?]: 202 [0], given: 134

Re: N is an integer . Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 18:43
Got it, thanks. I was getting confused because of the similarity between this and the other question I had!

Zarrolou wrote:
WholeLottaLove wrote:
Wait, why does N = 0?

If $$N>0$$ then $$N=-N$$ or $$2N=0$$ or $$N=0$$ but since 0 is not in the interval $$>0$$, this is not a valid solution.

Kudos [?]: 202 [0], given: 134

Senior Manager
Joined: 13 May 2013
Posts: 460

Kudos [?]: 202 [0], given: 134

Re: N is an integer. Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 18:48
A) |N|= -N
That is true if N\leq{0}
Not sufficient to say that is negative (could be 0).

I hate to ask one more stupid question but...

How is |n| = -n if n≤0? If n is zero then wouldn't |n| just be n, as opposed to -n?

Kudos [?]: 202 [0], given: 134

VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1120

Kudos [?]: 2375 [1], given: 219

Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Re: N is an integer. Is N negative ? [#permalink]

### Show Tags

18 Jun 2013, 18:51
1
KUDOS
WholeLottaLove wrote:
A) |N|= -N
That is true if N\leq{0}
Not sufficient to say that is negative (could be 0).

I hate to ask one more stupid question but...

How is |n| = -n if n≤0? If n is zero then wouldn't |n| just be n, as opposed to -n?

Given $$|N|= -N$$, if $$N=0$$ you get $$|0|=-0$$ which still holds true ( $$0=0$$ )
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Kudos [?]: 2375 [1], given: 219

Senior Manager
Joined: 13 May 2013
Posts: 460

Kudos [?]: 202 [0], given: 134

Re: N is an integer. Is N negative ? [#permalink]

### Show Tags

27 Jun 2013, 16:15
N is an integer. Is N negative ?

(1) |N| = -N
-N is equal to an absolute value which means it must be positive. So, -N = -(-N). However, N can also equal zero as |0| = -0 is valid. N ≤ 0 but we can't be sure if N is negative or not.
INSUFFICIENT

(2) N^4 = N^2
N^4 = N^2 when n = -1, 0, 1. Again we can't tell if N is positive, zero or negative.

1+2) 1) tells us that n is zero or negative and 2) tells us that n is negative or zero or positive. Therefore, N could be negative or zero.
INSUFFICIENT

(E)

Kudos [?]: 202 [0], given: 134

Non-Human User
Joined: 09 Sep 2013
Posts: 15579

Kudos [?]: 283 [0], given: 0

Re: N is an integer. Is N negative ? [#permalink]

### Show Tags

12 Aug 2017, 04:18
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.
_________________

Kudos [?]: 283 [0], given: 0

Senior Manager
Joined: 06 Jul 2016
Posts: 425

Kudos [?]: 124 [0], given: 98

Location: Singapore
Concentration: Strategy, Finance
Re: N is an integer. Is N negative ? [#permalink]

### Show Tags

12 Aug 2017, 05:42
guerrero25 wrote:
N is an integer. Is N negative ?

(1) |N| = -N
(2) N^4 = N^2

1) |N| = -N
=> N ≤ 0
=> N could be 0, -1, -2,...
Insufficient.

2) $$N^4$$ = $$N^2$$
=> N = -1, 0, 1
Insufficient.

1+2)
N could be 0 or -1.
Insufficient.

_________________

Put in the work, and that dream score is yours!

Kudos [?]: 124 [0], given: 98

Re: N is an integer. Is N negative ?   [#permalink] 12 Aug 2017, 05:42
Display posts from previous: Sort by