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

 It is currently 15 Dec 2019, 19:25

### 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

# What is the value of 4n – 5m?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 59730
What is the value of 4n – 5m?  [#permalink]

### Show Tags

13 Dec 2015, 05:27
1
2
00:00

Difficulty:

15% (low)

Question Stats:

80% (00:52) correct 20% (01:02) wrong based on 91 sessions

### HideShow timer Statistics

What is the value of 4n – 5m?

(1) n/5 = m/4
(2) n/4 = m/5

_________________
Current Student
Joined: 21 Jul 2013
Posts: 105
WE: Securities Sales and Trading (Commercial Banking)
Re: What is the value of 4n – 5m?  [#permalink]

### Show Tags

17 Dec 2015, 06:45
Bunuel wrote:
What is the value of 4n – 5m?

(1) n/5 = m/4
(2) n/4 = m/5

(1) n/5 = m/4
4n = 5m

replace 4n = 5m in the original question
4n – 5m
= 5m - 5m
= 0

SUFFICIENT

(2) n/4 = m/5
5n = 4m
n = 4/5 m

replace n = 4/5 m in the original question
4n – 5m
= 4(4/5 m) - 5m
= 16/5 m - 5m
= -9/5 m
we still do not know what is m

INSUFFICIENT

My Choice : A
Manager
Joined: 29 Jul 2015
Posts: 57
Location: Australia
GMAT 1: 680 Q49 V33
GPA: 3.25
WE: Business Development (Energy and Utilities)
Re: What is the value of 4n – 5m?  [#permalink]

### Show Tags

17 Dec 2015, 18:26
We are asked to find the value of 4n-5m.

Statement 1:
n/5 = m/4

This gives us 4n=5m or 4n-5m=0 SUFFICIENT.

Statement 2:

n/4 = m/5

5n=4m which implies n= 4m/5

Substituting value of n in 4n-5m we have - 4(4m/5)-5m i.e. m(-9/5) which clearly depends on value of m.

Hence insufficient.

Intern
Joined: 22 Nov 2015
Posts: 17
Re: What is the value of 4n – 5m?  [#permalink]

### Show Tags

19 Dec 2015, 07:11
According to question: 4n-5m=?
Statement 1: n/5=m/4 => 4n=5m=> substitute=> 5m-5m=0 SUFF
Statement 2: n/4=m/5=>5n=4m=> subtitute either in value of m or n will still leave one variable => no value. INSUFF
Ans: A
Intern
Joined: 18 Feb 2016
Posts: 1
Re: What is the value of 4n – 5m?  [#permalink]

### Show Tags

18 Feb 2016, 18:56
Hi,

I have a question. How come we can't sub numbers instead of N and M and test sufficiency that way ?

a) 20 and 25 for n and m
b) 40 and 5 for n and m

hence using both you can get answers.

Is the whole point of data sufficiency questions to figure out ONE answer. What I mean by that, if there are multiple numbers we can plug in for n and m that makes it insufficient right ? .. That would make sense why A is the answer.

Thanks,
Non-Human User
Joined: 09 Sep 2013
Posts: 13742
Re: What is the value of 4n – 5m?  [#permalink]

### Show Tags

17 Oct 2019, 20:54
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.
_________________
Re: What is the value of 4n – 5m?   [#permalink] 17 Oct 2019, 20:54
Display posts from previous: Sort by