GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Oct 2018, 13:42

### 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

# If |m+5|−5 = m, which of the following must be true?

Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 21 Oct 2013
Posts: 420
If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

02 Aug 2014, 07:28
3
14
00:00

Difficulty:

55% (hard)

Question Stats:

59% (01:35) correct 41% (01:38) wrong based on 469 sessions

### HideShow timer Statistics

If |m+5|−5 = m, which of the following must be true?

A. m = 0
B. m = −10
C. m is a multiple of 5.
D. m ≥ −5
E. |m+5| > 0
Math Expert
Joined: 02 Sep 2009
Posts: 50002
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

02 Aug 2014, 08:46
6
5
goodyear2013 wrote:
If |m+5|−5 = m, which of the following must be true?

A. m = 0
B. m = −10
C. m is a multiple of 5.
D. m ≥ −5
E. |m+5| > 0

|m + 5| - 5 = m --> |m + 5| = m + 5.

We know that |x| = x, when $$x\geq{0}$$. Therefore, from |m + 5| = m + 5 it follows that $$m+5\geq{0}$$ --> $$m\geq{-5}$$.

P.S. |x| = -x, when $$x\leq{0}$$.
_________________
##### General Discussion
Manager
Joined: 22 Feb 2009
Posts: 175
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

03 Aug 2014, 00:26
1
goodyear2013 wrote:
If |m+5|−5 = m, which of the following must be true?

A. m = 0
B. m = −10
C. m is a multiple of 5.
D. m ≥ −5
E. |m+5| > 0

Case 1 : |m+5| = 0, then m= -5
|-5+5|−5 = -5 --> true

Case 2; |m+5| < 0, then m< -5
|m+5|−5 = -m - 5 -5 = m , then m = -5 --> false

Case 3: Case 2; |m+5| > 0, then m> -5
|m+5|−5 = m+5 -5 = m , then m = m --> always true

Only case 1 and 3 satisfy the equation, so D is the answer.
_________________

.........................................................................
+1 Kudos please, if you like my post

Intern
Joined: 16 Jun 2014
Posts: 12
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

03 Aug 2014, 23:46
Make a positive and a negative case

|m + 5| - 5 = m --> |m + 5| = m + 5

Positive:
m + 5 = m + 5 --> m = 0

Negative
m + 5 = -m - 5
2m = -10 --> m = -5

As you can see only answer D satisfy both conditions.
Director
Status: I don't stop when I'm Tired,I stop when I'm done
Joined: 11 May 2014
Posts: 542
GPA: 2.81
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

23 Aug 2015, 05:31
My answer is D.only multiple number picking works on the answer choice D
_________________

Md. Abdur Rakib

Please Press +1 Kudos,If it helps
Sentence Correction-Collection of Ron Purewal's "elliptical construction/analogies" for SC Challenges

Manager
Joined: 10 Jun 2015
Posts: 118
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

23 Aug 2015, 06:25
goodyear2013 wrote:
If |m+5|−5 = m, which of the following must be true?

A. m = 0
B. m = −10
C. m is a multiple of 5.
D. m ≥ −5
E. |m+5| > 0

|m+5| = m+5
Either m+5 = m+5 or -m-5 = m+5
In the second case, m=-5
When m<-5, the equation does not hold true. LHS is always positive and RHS is negative.
Therefore, m> or = -5
Manhattan Prep Instructor
Joined: 04 Dec 2015
Posts: 629
GMAT 1: 790 Q51 V49
GRE 1: Q170 V170
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

30 Jul 2018, 13:53
Michellegeorge777 wrote:
Why is answer choice (A) wrong?

You're looking for a statement that must be true. In other words, the right answer will be something that definitely has to be true no matter what.

Does m have to equal 0? No, because m could also equal a lot of other different numbers: m could be 1, 10, or 100. Since (A) doesn't necessarily have to be the case - it could be true, it could be false, depending on what m is - it isn't the right answer.

You can think about this like a Data Sufficiency problem. The information you know is what the question says: you know that |m + 5| - 5 = m. You don't know anything else about m. Can you conclude that m must equal 0? No, you don't have enough info to conclude that.

In contrast, you can conclude that m definitely must be greater than or equal to -5.
_________________

Chelsey Cooley | Manhattan Prep Instructor | Seattle and Online

My upcoming GMAT trial classes | GMAT blog archive

Intern
Joined: 20 Aug 2017
Posts: 23
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

31 Jul 2018, 00:12
I agree with D. But why E is wrong? |m+5| should be always positive.
Math Expert
Joined: 02 Sep 2009
Posts: 50002
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

31 Jul 2018, 00:22
sghoshgt wrote:
I agree with D. But why E is wrong? |m+5| should be always positive.

Absolute value is always non-negative, not positive. So, it could be 0 as well. |m + 5| = 0 for m = -5.
_________________
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3888
Location: United States (CA)
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

### Show Tags

01 Aug 2018, 16:29
goodyear2013 wrote:
If |m+5|−5 = m, which of the following must be true?

A. m = 0
B. m = −10
C. m is a multiple of 5.
D. m ≥ −5
E. |m+5| > 0

Isolating the absolute value, we have:

|m + 5| = m + 5

We see that the absolute value of an expression is equal to the expression itself. That could only be true if the expression is nonnegative. That is,

m + 5 ≥ 0

m ≥ -5

_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: If |m+5|−5 = m, which of the following must be true? &nbs [#permalink] 01 Aug 2018, 16:29
Display posts from previous: Sort by