NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 21:24 It is currently 25 Apr 2024, 21:24
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

If 11m − n = p, then which of the following represents the a

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
avatar
kennavalkyrie
Intern
Intern
Joined: 27 May 2014
Posts: 1
Own Kudos [?]: 8 [8]
Given Kudos: 4
Send PM
If 11m − n = p, then which of the following represents the a [#permalink] New post   Updated on: 27 May 2014, 13:31
4
Kudos
4
Bookmarks
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

91% (01:08) correct 9% (01:49) wrong based on 159 sessions
Hide Show timer Statistics
If 11m − n = p, then which of the following represents the average (arithmetic mean) of m, n, and p, in terms of m?

(A) 2m −1
(B) 4m
(C) 6m
(D) m/5
(E) 6m/5

Show Spoiler
The answer is 4m, but I got 2m, what did I do wrong?
I got: p=11m-n 11m-n-p+11m+p+n\frac{}{11}=22/11m=2m

n=-p+11m

m=p+n/11
ShowHide Answer
Official Answer
B

Originally posted by kennavalkyrie on 27 May 2014, 12:51.
Last edited by Bunuel on 27 May 2014, 13:31, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
User avatar
G
mikemcgarry
Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4452
Own Kudos [?]: 28573 [2]
Given Kudos: 130
Re: Arithmetic Mean Question [#permalink] New post   27 May 2014, 13:15
2
Kudos
Expert Reply
kennavalkyrie wrote:
If 11m-n=p, then which of the following represents the average of m, n, and p, in terms of m?

The answer is 4m, but I got 2m, what did I do wrong?
I got: p=11m-n 11m-n-p+11m+p+n\frac{}{11}=22/11m=2m

n=-p+11m

m=p+n/11

Dear kennavalkyrie,
I'm happy to respond. :-) Unfortunately, the way you have presented your work is unclear enough that I cannot follow what you were thinking. I think part of the problem, in that last line, is that when you divide by 11, you need to divide every term. Relatedly, I think you are neglecting grouping symbols, and overlooking these core mathematical symbols leads to a large number of mistakes. See:
https://magoosh.com/gmat/2013/gmat-quant ... g-symbols/

I will show you the solution:
11m - n = p
Add n to both sides:
11m = n + p
Add m to both sides:
12m = n + p + m
Now, divide both sides by 3
4m = (n + p + m)/3 = the average of n, p, and m

Does all this make sense?
Mike :-)
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92915
Own Kudos [?]: 619048 [2]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
Re: Arithmetic Mean Question [#permalink] New post   27 May 2014, 13:31
2
Kudos
Expert Reply
kennavalkyrie wrote:
If 11m-n=p, then which of the following represents the average of m, n, and p, in terms of m?

The answer is 4m, but I got 2m, what did I do wrong?
I got: p=11m-n 11m-n-p+11m+p+n\frac{}{11}=22/11m=2m

n=-p+11m

m=p+n/11


If 11m − n = p, then which of the following represents the average (arithmetic mean) of m, n, and p, in terms of m?

(A) 2m −1
(B) 4m
(C) 6m
(D) m/5
(E) 6m/5

The average of m, n, and p is \(\frac{m+n+p}{3}\).

Since 11m − n = p, then n + p = 11m. Substitute the value of n + p into the average expression: \(\frac{m+n+p}{3}=\frac{m+11m}{3}=\frac{12m}{3}=4m\).

Answer: B.

P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 1, 3, 5, and 8. Thank you.
User avatar
L
BrentGMATPrepNow
GMAT Club Legend
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6820
Own Kudos [?]: 29934 [4]
Given Kudos: 799
Location: Canada
Send PM
Re: If 11m − n = p, then which of the following represents the a [#permalink] New post   17 Sep 2016, 04:48
2
Kudos
2
Bookmarks
Expert Reply
Top Contributor
kennavalkyrie wrote:
If 11m − n = p, then which of the following represents the average (arithmetic mean) of m, n, and p, in terms of m?

(A) 2m −1
(B) 4m
(C) 6m
(D) m/5
(E) 6m/5


Another approach (similar to Bunuel's):

Average = (m + n + p)/3
Replace p with 11m - n, to get:
Average = [m + n + (11m - n)]/3
= 12m/3
= 4m
Answer:
Show Spoiler
B


Related Video:


Cheers,
Brent
User avatar
paidlukkha
Senior Manager
Senior Manager
Joined: 11 Nov 2014
Posts: 263
Own Kudos [?]: 328 [0]
Given Kudos: 17
Location: India
Concentration: Finance, International Business
Schools: ISB '18 Great Lakes '18 SPJ PGPM"17 LBS '18 NTU '18 NUS '18
WE:Project Management (Telecommunications)
Send PM
GMAT ToolKit User
Re: If 11m − n = p, then which of the following represents the a [#permalink] New post   17 Sep 2016, 07:41
m+n+p/3
=m+n+11m-n/3
=12m/3
=4m

B
User avatar
G
a70
Intern
Intern
Joined: 21 May 2016
Posts: 24
Own Kudos [?]: 141 [0]
Given Kudos: 8
Send PM
GMAT ToolKit User
Re: If 11m − n = p, then which of the following represents the a [#permalink] New post   26 Sep 2018, 23:04
Arithmetic mean=(m+n+p)/3
From the equation we have
11m-n=p
11m=p+n
Substituting the value pf p+n
AM=12m/3=4m
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22055 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: If 11m − n = p, then which of the following represents the a [#permalink] New post   27 Sep 2018, 17:35
Expert Reply
kennavalkyrie wrote:
If 11m − n = p, then which of the following represents the average (arithmetic mean) of m, n, and p, in terms of m?

(A) 2m −1
(B) 4m
(C) 6m
(D) m/5
(E) 6m/5


We have the following expression for the average of m, n, and p:

(m + n + p)/3

Substituting (11m - n) for p, we obtain:

(m + n + 11m - n)/3 = 12m/3 = 4m

Answer: B
GMAT Club Bot
gmatclubot
Re: If 11m − n = p, then which of the following represents the a [#permalink]
27 Sep 2018, 17:35
Moderators:
Bunuel
Math Expert
92915 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions