It is currently 17 Oct 2017, 08:37

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If x > y > z, which cannot be the average (arithmetic mean) of x, y an

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41871

Kudos [?]: 128551 [0], given: 12180

If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 04 May 2017, 01:49
Expert's post
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

79% (00:45) correct 21% (00:48) wrong based on 97 sessions

HideShow timer Statistics

Kudos [?]: 128551 [0], given: 12180

Expert Post
Top Contributor
SVP
SVP
User avatar
G
Joined: 12 Sep 2015
Posts: 1793

Kudos [?]: 2444 [0], given: 356

Location: Canada
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 04 May 2017, 06:33
Expert's post
Top Contributor
Bunuel wrote:
If x > y > z, which cannot be the average (arithmetic mean) of x, y and z?

A. x
B. y
C. x – 1
D. z + 1
E. (z + y)/2


Nice!

The average (mean) is meant to provide a rough idea of what the numbers look like.
So, since x is the greatest value, it cannot be the average.
Answer:
[Reveal] Spoiler:
A


RELATED VIDEO

_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Kudos [?]: 2444 [0], given: 356

1 KUDOS received
BSchool Forum Moderator
User avatar
P
Joined: 12 Aug 2015
Posts: 2212

Kudos [?]: 836 [1], given: 595

GMAT ToolKit User Premium Member CAT Tests
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 04 May 2017, 10:04
1
This post received
KUDOS
Here is what i did on this question -->

Using the definition of arithmetic mean -> Mean is a number that can be used to replace each element of the data set.
If mean is X --> Number can be written as X,X,X
But the other two numbers are less than X.

Hence Mean can never be X.

Smash that A.

_________________

Give me a hell yeah ...!!!!!

Kudos [?]: 836 [1], given: 595

Senior Manager
Senior Manager
avatar
B
Joined: 06 Dec 2016
Posts: 257

Kudos [?]: 23 [0], given: 10

Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 04 May 2017, 11:51
If X is the biggest number then X can not be the mean. If you need more evidence, plug in numbers to see.
The answer is A

Kudos [?]: 23 [0], given: 10

Director
Director
avatar
S
Joined: 21 Mar 2016
Posts: 529

Kudos [?]: 28 [0], given: 96

Reviews Badge CAT Tests
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 04 May 2017, 23:13
answer shud be in between x and z...

only A fits in ,,,

ans A

Kudos [?]: 28 [0], given: 96

VP
VP
avatar
G
Joined: 26 Mar 2013
Posts: 1258

Kudos [?]: 285 [0], given: 163

Reviews Badge CAT Tests
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 05 May 2017, 00:59
GMATPrepNow wrote:
Bunuel wrote:
If x > y > z, which cannot be the average (arithmetic mean) of x, y and z?

A. x
B. y
C. x – 1
D. z + 1
E. (z + y)/2


Nice!

The average (mean) is meant to provide a rough idea of what the numbers look like.
So, since x is the greatest value, it cannot be the average.
Answer:
[Reveal] Spoiler:
A



Dear Brent,

Although it is clear for me the right answer, I wonder about how choice E would be a mean for 3 numbers in the prompt?

Thanks

Kudos [?]: 285 [0], given: 163

1 KUDOS received
BSchool Forum Moderator
User avatar
P
Joined: 12 Aug 2015
Posts: 2212

Kudos [?]: 836 [1], given: 595

GMAT ToolKit User Premium Member CAT Tests
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 08 Aug 2017, 02:28
1
This post received
KUDOS
Hey chetan2u
There is no doubt in my mind that A is correct option.


But I cannot fathom why E isn't the option too.

Here is what I feel.

For E to be correct =>
x+y+z/3 = y+z/2

Hence y+z=2x

But since y<x and z<x

This can never happen.

Hence E will is correct too.

Hence A and E are both correct.


What am I missing ?


Best
Stone
_________________

Give me a hell yeah ...!!!!!

Kudos [?]: 836 [1], given: 595

Expert Post
2 KUDOS received
Math Forum Moderator
avatar
P
Joined: 02 Aug 2009
Posts: 4966

Kudos [?]: 5449 [2], given: 112

Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 08 Aug 2017, 03:23
2
This post received
KUDOS
Expert's post
stonecold wrote:
Hey chetan2u
There is no doubt in my mind that A is correct option.


But I cannot fathom why E isn't the option too.

Here is what I feel.

For E to be correct =>
x+y+z/3 = y+z/2

Hence y+z=2x

But since y<x and z<x

This can never happen.

Hence E will is correct too.

Hence A and E are both correct.


What am I missing ?


Best
Stone


Hi stone,

I totally agree with you. Your approach is also absolutely correct..
Other wise...
(z+y)/2 is the average of z and y..
So ONLY way that even after adding a new number, the means remain the same is when the new number is SAME as the average...
But in this case x becomes less than y..
Not possible so E is the answer..

So the choice E could be
1) (x+z)/2 or
2) z + y/2

Bunuel pl relook in the Choice E. There is some Typo
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 5449 [2], given: 112

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41871

Kudos [?]: 128551 [1], given: 12180

Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 08 Aug 2017, 03:37
1
This post received
KUDOS
Expert's post
chetan2u wrote:
stonecold wrote:
Hey chetan2u
There is no doubt in my mind that A is correct option.


But I cannot fathom why E isn't the option too.

Here is what I feel.

For E to be correct =>
x+y+z/3 = y+z/2

Hence y+z=2x

But since y<x and z<x

This can never happen.

Hence E will is correct too.

Hence A and E are both correct.


What am I missing ?


Best
Stone


Hi stone,

I totally agree with you. Your approach is also absolutely correct..
Other wise...
(z+y)/2 is the average of z and y..
So ONLY way that even after adding a new number, the means remain the same is when the new number is SAME as the average...
But in this case x becomes less than y..
Not possible so E is the answer..

So the choice E could be
1) (x+z)/2 or
2) z + y/2

Bunuel pl relook in the Choice E. There is some Typo

______________
Edited. Thank you.
_________________

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

Kudos [?]: 128551 [1], given: 12180

Expert Post
Target Test Prep Representative
User avatar
S
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 1619

Kudos [?]: 835 [0], given: 2

Location: United States (CA)
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 10 Aug 2017, 10:49
Bunuel wrote:
If x > y > z, which cannot be the average (arithmetic mean) of x, y and z?

A. x
B. y
C. x – 1
D. z + 1
E. (z + x)/2


We are given three different-valued quantities x, y, z, with x having the largest value. Thus, the average of the three quantities can’t be x (the average of any set of numbers is always less than the largest number in the set).

Answer: A
_________________

Scott Woodbury-Stewart
Founder and CEO

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

Kudos [?]: 835 [0], given: 2

Expert Post
Top Contributor
SVP
SVP
User avatar
G
Joined: 12 Sep 2015
Posts: 1793

Kudos [?]: 2444 [0], given: 356

Location: Canada
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 20 Sep 2017, 15:42
Expert's post
Top Contributor
Mo2men wrote:

Dear Brent,

Although it is clear for me the right answer, I wonder about how choice E would be a mean for 3 numbers in the prompt?

Thanks


E) If x = 3, y = 2 and z = 1, then the average of x, y, and z is 2, which is the same as (z+x)/2.
Since the average CAN equal (z+x)/2, we can ELIMINATE E
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Kudos [?]: 2444 [0], given: 356

Expert Post
Top Contributor
SVP
SVP
User avatar
G
Joined: 12 Sep 2015
Posts: 1793

Kudos [?]: 2444 [0], given: 356

Location: Canada
Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an [#permalink]

Show Tags

New post 20 Sep 2017, 15:45
Expert's post
Top Contributor
Bunuel wrote:
If x > y > z, which cannot be the average (arithmetic mean) of x, y and z?

A. x
B. y
C. x – 1
D. z + 1
E. (z + x)/2


Another approach is to apply some number sense.

Since y and z are smaller than x, we can say....
y = a number smaller than x
z = another number smaller than x

So.....
The average of x, y and z = the average of x, a number smaller than x, and another number smaller than x
= (x + a number smaller than x + another number smaller than x)/3
= (a number that's LESS THAN 3x)/3
= a number LESS THAN x

Since the average must be LESS THAN x, the average cannot equal x

Answer:
[Reveal] Spoiler:
A


RELATED VIDEO:



Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Kudos [?]: 2444 [0], given: 356

Re: If x > y > z, which cannot be the average (arithmetic mean) of x, y an   [#permalink] 20 Sep 2017, 15:45
Display posts from previous: Sort by

If x > y > z, which cannot be the average (arithmetic mean) of x, y an

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.