It is currently 19 Oct 2017, 22:46

### 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 M < 0? 1. -M = |-M| 2. M^2 =9

Author Message
CEO
Joined: 21 Jan 2007
Posts: 2734

Kudos [?]: 1046 [0], given: 4

Location: New York City
Is M < 0? 1. -M = |-M| 2. M^2 =9 [#permalink]

### Show Tags

21 Oct 2007, 20:47
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Is M < 0?

1. -M = |-M|
2. M^2 =9

Kudos [?]: 1046 [0], given: 4

Director
Joined: 03 May 2007
Posts: 867

Kudos [?]: 264 [0], given: 7

Schools: University of Chicago, Wharton School
Re: Challenge - Absolute Values [#permalink]

### Show Tags

21 Oct 2007, 20:49
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

Kudos [?]: 264 [0], given: 7

Director
Joined: 09 Aug 2006
Posts: 754

Kudos [?]: 255 [0], given: 0

Re: Challenge - Absolute Values [#permalink]

### Show Tags

21 Oct 2007, 22:01
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Get A.

Stat 2: Started with stat 2 since it looked simpler. M can be 3 or -3. Insuff.

ACE left.

Stat 1: for -M to be equal to |-M|, M has to be negative; suff.

Plugging in numbers will prove this:

M = 4, -M = -4, |-M| = |-4| = 4; -4 is not equal to 4; M cannot be +ve
M = -4, -M = 4, |-M| = |4| = 4; 4 = 4; M has to be -ve

Kudos [?]: 255 [0], given: 0

Senior Manager
Joined: 27 Aug 2007
Posts: 253

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

Re: Challenge - Absolute Values [#permalink]

### Show Tags

21 Oct 2007, 22:16
Fistail wrote:
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

I think the answer is C,

1) INSUFF, Fistal you forgot about 0
2) INSUFF -3 or +3

Together suff since it should be less or equal to zero and -3 or +3, in other words -3

Ans: C

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

Director
Joined: 03 May 2007
Posts: 867

Kudos [?]: 264 [0], given: 7

Schools: University of Chicago, Wharton School
Re: Challenge - Absolute Values [#permalink]

### Show Tags

21 Oct 2007, 23:05
Ferihere wrote:
Fistail wrote:
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

I think the answer is C,

1) INSUFF, Fistal you forgot about 0
2) INSUFF -3 or +3

Together suff since it should be less or equal to zero and -3 or +3, in other words -3

Ans: C

oh yah. thats a good catch on great trap.
you are correct. thanks.

Kudos [?]: 264 [0], given: 7

Manager
Joined: 01 Oct 2007
Posts: 138

Kudos [?]: 5 [0], given: 0

Re: Challenge - Absolute Values [#permalink]

### Show Tags

22 Oct 2007, 03:50
Fistail wrote:
Ferihere wrote:
Fistail wrote:
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

I think the answer is C,

1) INSUFF, Fistal you forgot about 0
2) INSUFF -3 or +3

Together suff since it should be less or equal to zero and -3 or +3, in other words -3

Ans: C

oh yah. thats a good catch on great trap.
you are correct. thanks.

Fistal, could you please tell me how to test it with value ZERO? please plese sir..

Kudos [?]: 5 [0], given: 0

Senior Manager
Joined: 04 Jan 2006
Posts: 276

Kudos [?]: 43 [0], given: 0

Re: Challenge - Absolute Values [#permalink]

### Show Tags

22 Oct 2007, 07:25
yash500 wrote:
Fistail wrote:
Ferihere wrote:
Fistail wrote:
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

I think the answer is C,

1) INSUFF, Fistal you forgot about 0
2) INSUFF -3 or +3

Together suff since it should be less or equal to zero and -3 or +3, in other words -3

Ans: C

oh yah. thats a good catch on great trap.
you are correct. thanks.

Fistal, could you please tell me how to test it with value ZERO? please plese sir..

Let me try to explain how to get the answer from 1. -M = |-M|

I) |-M| = |M| ; from |a| = |-a|
II) |M| = -M

Case 1: if M > 0, then we get M = -M
2M = 0
M = 0

Case 2: if M < 0, then we get -M = -M
M - M = 0
M = Real Number
But this Real Number is limited by the constraint M < 0. Therefore, the answer for case 2 is M < 0

Case 1 + Case 2 we get M <= 0.

At the end, the answer will be (C)

Kudos [?]: 43 [0], given: 0

Director
Joined: 03 May 2007
Posts: 867

Kudos [?]: 264 [0], given: 7

Schools: University of Chicago, Wharton School
Re: Challenge - Absolute Values [#permalink]

### Show Tags

23 Oct 2007, 12:22
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

hey bmwhype2,

Can you post the OAs to your questions? most of the questions you submitted do not have OAs.

Kudos [?]: 264 [0], given: 7

Senior Manager
Joined: 11 Sep 2005
Posts: 313

Kudos [?]: 372 [0], given: 0

Re: Challenge - Absolute Values [#permalink]

### Show Tags

23 Oct 2007, 13:24
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

A..........info 1 gives M<0
info 2 insuff.....

Kudos [?]: 372 [0], given: 0

Senior Manager
Joined: 11 Sep 2005
Posts: 313

Kudos [?]: 372 [0], given: 0

Re: Challenge - Absolute Values [#permalink]

### Show Tags

23 Oct 2007, 13:26
Fistail wrote:
Ferihere wrote:
Fistail wrote:
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

Should be A. if -m is +ve, m should be -ve.

I think the answer is C,

1) INSUFF, Fistal you forgot about 0
2) INSUFF -3 or +3

Together suff since it should be less or equal to zero and -3 or +3, in other words -3

Ans: C

oh yah. thats a good catch on great trap.
you are correct. thanks.

Oopss missed ZERO.......C is the right answer!

Kudos [?]: 372 [0], given: 0

CEO
Joined: 21 Jan 2007
Posts: 2734

Kudos [?]: 1046 [0], given: 4

Location: New York City
Re: Challenge - Absolute Values [#permalink]

### Show Tags

04 Nov 2007, 03:27
bmwhype2 wrote:
Is M < 0?

1. -M = |-M|
2. M^2 =9

This is how i solved it.

Statement (1) tells us the right side is a non negative number. Absolute values are NON NEGATIVE. Therefore, the right side is 0 or a positive #. The left side is negative M. The only way the left side (with its negative M) can equal the right side (with its positive or zero value) is if M is a negative or zero value. We have dont have an exact value for M so we cant answer the stem. INSUFF

Statement (1) tells us m^2 = 9, giving us m=3 and m=-3. Two values. INSUFF

Taken together, M=-3. Stem is answerable. Therefore C.

Kudos [?]: 1046 [0], given: 4

Re: Challenge - Absolute Values   [#permalink] 04 Nov 2007, 03:27
Display posts from previous: Sort by