Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

 It is currently 18 Jul 2019, 23:08 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  # M01-17

Author Message
TAGS:

### Hide Tags

Director  V
Joined: 12 Feb 2015
Posts: 875

### Show Tags

1
Only thing I would like to highlight once again for this problem is that have a set of numbers to test on each and every DS question. For statement (1) it was very important to test for zero. It does not strike naturally for this statement that m could be zero.

Hence develop a habit to test numbers systematically. Use a standard set of numbers during your practice sessions so that this becomes a habit. After reading the constraints mentioned in question stem and the 2 statements, you could test for (assuming no constraints) -2,$$\frac{-3}{2}$$,-1,$$\frac{-1}{2}$$,0,$$\frac{1}{2}$$,1,$$\frac{3}{2}$$ and 2.

Please read my overall understanding on DS questions and few useful tips:-

https://gmatclub.com/forum/data-suffici ... l#p2073589
_________________
"Please hit +1 Kudos if you like this post" _________________
Manish "Only I can change my life. No one can do it for me"
Intern  B
Joined: 09 Apr 2018
Posts: 24
Location: India
GMAT 1: 690 Q47 V38 GMAT 2: 710 Q49 V36 GPA: 3.7

### Show Tags

Hi,

I re read the solution, but unable to understand the flaw in my logic
Math Expert V
Joined: 02 Sep 2009
Posts: 56260

### Show Tags

Fervids77 wrote:
Hi,

I re read the solution, but unable to understand the flaw in my logic

$$|m|=-m$$, means that $$m\leq 0$$, so $$m$$ could be either negative or zero. Notice that $$|m|=-m$$ holds if m = 0 too.
_________________
Intern  B
Joined: 09 Apr 2018
Posts: 24
Location: India
GMAT 1: 690 Q47 V38 GMAT 2: 710 Q49 V36 GPA: 3.7

### Show Tags

Hi,

Thanks for the response. It is clear now
So if the question was is m>=0 then statement would be sufficient
Manager  S
Joined: 21 Jul 2018
Posts: 193

### Show Tags

Bunuel wrote:
Is $$m \lt 0$$?

(1) $$-m = |-m|$$

(2) $$m^2 = 9$$

Hi Bunuel, chetan2u

I read solution but not able find my doubt, not sure if I have missed anything.

I think statement 1 is only true when "m" is negative as RHS |-m| is always going to be positive no matter what is value of "m" and LHS as per statement is "-m" which can be only be converted to positive when value of "m" is negative to make it equal to RHS as "- * - = +"

_________________
______________________________
Press +1 Kudos if my post helped you a little and help me to ulcock the tests Wish you all success

I'd appreciate learning about the grammatical errors in my posts

Please let me know if I'm wrong somewhere and help me to learn Math Expert V
Joined: 02 Sep 2009
Posts: 56260

### Show Tags

Gmatprep550 wrote:
Bunuel wrote:
Is $$m \lt 0$$?

(1) $$-m = |-m|$$

(2) $$m^2 = 9$$

Hi Bunuel, chetan2u

I read solution but not able find my doubt, not sure if I have missed anything.

I think statement 1 is only true when "m" is negative as RHS |-m| is always going to be positive no matter what is value of "m" and LHS as per statement is "-m" which can be only be converted to positive when value of "m" is negative to make it equal to RHS as "- * - = +"

$$-m=|-m|$$ holds for 0 too: -0 = 0 = |-0|.
_________________
GMAT Club Legend  D
Joined: 18 Aug 2017
Posts: 4247
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)

### Show Tags

Bunuel wrote:
Is $$m \lt 0$$?

(1) $$-m = |-m|$$

(2) $$m^2 = 9$$

#1
to be true , m can be -ve or 0 ;insufficient
#2
m=+/-3
insufficient
from 1 & 2
m= -3
IMO C
_________________
If you liked my solution then please give Kudos. Kudos encourage active discussions.
Director  P
Joined: 14 Feb 2017
Posts: 711
Location: Australia
Concentration: Technology, Strategy
GMAT 1: 560 Q41 V26 GMAT 2: 550 Q43 V23 GMAT 3: 650 Q47 V33 GPA: 2.61
WE: Management Consulting (Consulting)

### Show Tags

Made a stupid mistake when solving this in a GMATClub test.

Is m<0?

(1)$$−m=|−m|$$

Test m= -1

-(-1) = |-1|
1=1
is m< 0 --> yes

Test m = 0
-0= |-0|
0=0
is m <0 --> No

---Insufficient

(2)$$m^2=9$$

m= + / - 3

Yes or No
Insufficient

(1)+(2)

If m = -3 the equation in (1) is satisfied since
-(-3) = |-3|
3=3

but if m= 3 the equation does not hold true
i.e.
Is -(3) = |3| ? No
-3 is not equal to 3 obviously

Therefore combined it must be true that m < 0
_________________
Goal: Q49, V41

+1 Kudos if you like my post pls! Re: M01-17   [#permalink] 28 Apr 2019, 18:55

Go to page   Previous    1   2   [ 28 posts ]

Display posts from previous: Sort by

# M01-17

Moderators: chetan2u, Bunuel  