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

It is currently 22 Aug 2018, 00:53

Close

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
Your Progress

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.

Close

Request Expert Reply

Confirm Cancel

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

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Senior Manager
Senior Manager
User avatar
Joined: 21 Oct 2013
Posts: 433
If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 02 Aug 2014, 07:28
3
13
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

58% (01:09) correct 42% (01:05) wrong based on 439 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
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48119
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 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 \(m+5\geq{0}\) --> \(m\geq{-5}\).

Answer: D.

P.S. |x| = -x, when \(x\leq{0}\).
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

General Discussion
Manager
Manager
User avatar
Joined: 22 Feb 2009
Posts: 189
GMAT ToolKit User
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 03 Aug 2014, 00:26
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
Intern
avatar
Joined: 16 Jun 2014
Posts: 12
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 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
Director
User avatar
B
Status: I don't stop when I'm Tired,I stop when I'm done
Joined: 11 May 2014
Posts: 551
Location: Bangladesh
Concentration: Finance, Leadership
GPA: 2.81
WE: Business Development (Real Estate)
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 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
Manager
User avatar
Joined: 10 Jun 2015
Posts: 120
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 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
User avatar
G
Joined: 04 Dec 2015
Posts: 589
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

New post 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.
_________________

Image

Chelsey Cooley | Manhattan Prep Instructor | Seattle and Online

My upcoming GMAT trial classes | GMAT blog archive

Intern
Intern
avatar
B
Joined: 20 Aug 2017
Posts: 22
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 31 Jul 2018, 00:12
I agree with D. But why E is wrong? |m+5| should be always positive.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48119
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 31 Jul 2018, 00:22
Target Test Prep Representative
User avatar
G
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3199
Location: United States (CA)
Re: If |m+5|−5 = m, which of the following must be true?  [#permalink]

Show Tags

New post 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

Answer: D
_________________

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

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

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.