BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Arithmetic mean

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 416
Joined: Tue Aug 30, 2011 2:18 pmFollowed by: 9 members
Location: Delhi, India
Thanked: 13 times

by vaibhavgupta » Sun Nov 06, 2011 12:08 pm
selango wrote:If y is a negative number greater than -8, is x greater than the average (arithmetic mean) of y and -8 ?

(1) On the number line, x is closer to -8 than it is to y.

(2) x = 4y

Source:Grockit
+1 for A

Looking for OA!! :)
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 86
Joined: Mon Sep 13, 2010 2:36 pmFollowed by: 2 members
Thanked: 29 times
GMAT Score:710

by thebigkats » Sun Nov 06, 2011 2:27 pm
Hi:

Y is between -8 and 0 (given that it is negative and greater than -8). Arithmetic mean of Y and -8 is a no halfway between Y and -8 ==> is a negative no

#1 --> x is closer to -8 than Y means that X could be <-8 or x could be between -8 and Y.
If X is <-8 than it is < average of -8 and Y (which is -8 < MEAN < Y)
If X is >-8 and is closer to -8 than Y then it is less than MEAN (which is equidistant from -8 and Y)
So #1 = sufficient

#2 --> X = 4Y. If Y== -1 than X=-4 and is > -4.5 (MEAN of -8 and Y)
If Y == -5 then X=-20 and is <MEAN
So not sufficient


HENCE ans = A
---------------------------------
Everything is possible in this world. Even the word Impossible says - I'm possible
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 134
Joined: Fri Jan 23, 2009 1:23 pmFollowed by: 15 members
Location: California
Thanked: 59 times

by dabral » Sun Nov 06, 2011 9:31 pm
Here is the original source of this problem that is based on GMATPrep and discussed in the following post:

https://www.beatthegmat.com/gmat-prep-in ... 89109.html

Read gmatboost and bblast's explanations.

Dabral
selango wrote:If y is a negative number greater than -8, is x greater than the average (arithmetic mean) of y and -8 ?

(1) On the number line, x is closer to -8 than it is to y.

(2) x = 4y

Source:Grockit
Free Video Explanations: 2021 GMAT OFFICIAL GUIDE.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Wed Jan 12, 2011 7:17 am

by Kyle from Ohio » Tue Nov 29, 2011 11:25 am
To Fabio:

In your explanation you state that y < 2x+8 or y < 8(y+1) or (y+1)/y < 1/8.

I understand how you got y < 2x+8 but where did you get y < 8(y
+1)? I think I am missing something there.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 90
Joined: Thu Nov 05, 2009 9:14 amFollowed by: 3 members
Thanked: 5 times

by immaculatesahai » Sun Dec 11, 2011 12:15 am
+1 for A
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 53
Joined: Sat Jul 17, 2010 3:56 am
Thanked: 1 times

by mourinhogmat1 » Wed Jan 04, 2012 6:59 pm
From stem we are asked, Is x>(y-8)/2 given y >-8 and its negative i.e. 0>y>-8.

From, Statement 2, x=4y
0>y>-8 From stem
0>4y>-32 Multiply throughout by 4
0>x>-32

Now if x=-1, y = -8 , Is x>(y-8)/2? YES
Now if x=-31, y = -8 , Is x>(y-8)/2? NO

So, statement 2 is INSUFFICIENT.

From, Statement 1, x is closer to -8 than it is to y.
|x+8|<|x-y|
Is x>(y-8)/2? given i.e. 0>y>-8.

Now if y = -1, x = -7 --> Is x>(y-8)/2? NO
Now if y = -4, x = -7 --> Is x>(y-8)/2? NO
Now if y = -6, x = -7.5 --> Is x>(y-8)/2? NO

Answer should be A.
I did it in 2.5 minutes, any shortcuts?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 934
Joined: Tue Nov 09, 2010 5:16 amFollowed by: 14 members
Location: AAMCHI MUMBAI LOCAL
Thanked: 63 times

by [email protected] » Mon Jan 23, 2012 3:20 am
Well I do not know how am I not getting the answer as A. I am getting the answer as E.

watever explanation u have given i read those but i have a doubt in this question...

If y is a negative number greater than -8, is x greater than the average (arithmetic mean) of y and -8 ?

(1) On the number line, x is closer to -8 than it is to y.

(2) x = 4y


Statement 1:

lets say that if y = -6 and x = -7, then the average of -6 and -8 is -7.

also x = -7

hence it can't be said that x will always be closer than the mean of y and -8.

according to me the answer is E......

I hope this helps...!!!
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

Whenever you feel that my post really helped you to learn something new, please press on the 'THANK' button.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1084
Joined: Fri Apr 15, 2011 2:33 pmFollowed by: 21 members
Thanked: 158 times

by pemdas » Thu Jan 26, 2012 3:15 am
[email protected] wrote:Well I do not know how am I not getting the answer as A. I am getting the answer as E.

watever explanation u have given i read those but i have a doubt in this question...
answer is A
-8<y<0, Question: Is 2x>y-8?

st(1) implies distance between x and -8 is shorter than the distance between x and y OR |x-(-8)|<|x-y|, Tip~ mode is convenient for measuring distance between the numbers on the number line.

|x+8|<|x-y|, Solve by squaring both sides, this will be quicker. x^2+16x+64<x^2-2xy+y^2, y^2-2xy-16x-64>0, y^2-2x(y+8)-64>0, (y^2-64)/(y+8)>2x, (y-8)(y+8)/(y+8)>2x, y-8>2x Sufficient to answer No

st(2) provides x=4y and by multiplying both sides by 2 we get 2x=8y. From the question we know -8<y<0 and for example two cases considered:
case a) y=-1, x=-4 and to answer the question 2x>y-8 we test -8>-1-8, Yes
case b) y=-7, x=-28 and test 2x>y-8 returns -56>-7-8, No
Not Sufficient.

~Tip, you can directly answer st(2) Not Sufficient as x=4y implies literally x and y can be everything and contradicts our question's constraint -8<x<0
Success doesn't come overnight!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 626
Joined: Fri Dec 23, 2011 2:50 amFollowed by: 10 members
Location: Ahmedabad
Thanked: 31 times

by ronnie1985 » Fri Feb 03, 2012 8:05 am
Make number line to answer these questions.
(A) is the answer.
Attachments
Line.jpg
Number line
Follow your passion, Success as perceived by others shall follow you
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 626
Joined: Fri Dec 23, 2011 2:50 amFollowed by: 10 members
Location: Ahmedabad
Thanked: 31 times

by ronnie1985 » Fri Mar 30, 2012 10:10 am
IMO (A)
QED
Follow your passion, Success as perceived by others shall follow you
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 22
Joined: Thu Jun 28, 2012 10:38 am

by surmilsehgal » Mon Aug 13, 2012 8:46 am
answer is E
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 37
Joined: Mon Oct 10, 2011 2:27 am
Thanked: 2 times

by ritzzzr » Thu Feb 14, 2013 3:47 am
A is the ans!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 171
Joined: Tue Jan 08, 2013 7:24 am
Thanked: 1 times

by rajeshsinghgmat » Tue Feb 19, 2013 10:21 am
D in answer
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 171
Joined: Tue Jan 08, 2013 7:24 am
Thanked: 1 times

by rajeshsinghgmat » Tue Feb 19, 2013 6:23 pm
A in answer
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply