Find all School-related info fast with the new School-Specific MBA Forum

It is currently 21 Dec 2014, 22:20

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If Set Z has a median of 19, what is the range of Set Z? (1)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 10 Dec 2007
Posts: 54
Followers: 1

Kudos [?]: 12 [0], given: 0

If Set Z has a median of 19, what is the range of Set Z? (1) [#permalink] New post 14 Jan 2008, 05:23
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If Set Z has a median of 19, what is the range of Set Z?

(1) Z = {18, 28, 11, x, 15, y}

(2) The average (arithmetic mean) of Set Z is 20.
A. Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not
B. Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not
C. Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient
D. EITHER statement BY ITSELF is sufficient to answer the question
E. Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question, requiring more data pertaining to the problem







[spoiler]OA is C[/spoiler]

Last edited by AVakil on 14 Jan 2008, 05:53, edited 1 time in total.
Expert Post
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3576
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 386

Kudos [?]: 1948 [0], given: 359

GMAT ToolKit User Premium Member
Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 05:40
Expert's post
C

1) z1={18, 28, 11, 20, 15, 20}: median=(18+20)/2=19, range=28-11=17
z2={18, 28, 11, 20, 15, 30}: median=(18+20)/2=19, range=30-11=19
insuff.

2) z1={18,20}: median=(18+20)/2=19, range=20-18=2
z2={17,21}: median=(17+21)/2=19, range=21-17=4
insuff.

1)&2). only z={18, 28, 11, 20, 15, 28} satisfies both conditions. suff.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Director
Director
User avatar
Joined: 03 Sep 2006
Posts: 885
Followers: 6

Kudos [?]: 200 [0], given: 33

Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 06:45
AVakil wrote:
If Set Z has a median of 19, what is the range of Set Z?

(1) Z = {18, 28, 11, x, 15, y}

(2) The average (arithmetic mean) of Set Z is 20.
A. Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not
B. Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not
C. Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient
D. EITHER statement BY ITSELF is sufficient to answer the question
E. Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question, requiring more data pertaining to the problem







[spoiler]OA is C[/spoiler]




Z = {11, 15, 18, x, 28, y}

We no nothing about x and y.

So it can be : x, 11,15,y,18,28..... in this case y=23 ( if median is 19) but range depends on x, which we can't determine. Further there can be several permutations for x and y. Thus (i) is insufficient.

From (ii)

We know only that x+y= 58. And nothing else, so insufficient.

But if we combine, (i) and (ii)

11, 15,18,20,28,38 Range = 38-11 = 27

10, 11,15,18,28,48 range = Range = 48-10 = 38

Thus insufficient.

The answer should be "E".
Expert Post
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3576
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 386

Kudos [?]: 1948 [0], given: 359

GMAT ToolKit User Premium Member
Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 07:11
Expert's post
LM wrote:
But if we combine, (i) and (ii)

11, 15,18,20,28,38 Range = 38-11 = 27

10, 11,15,18,28,48 range = Range = 48-10 = 38

Thus insufficient.

The answer should be "E".


median of {10, 11,15,18,28,48} is (15+18)/2=16.5<19 that contradicts Q.
the average of {11,15,18,20,28,38} is 21.7>20 that contradicts ii
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Director
Director
avatar
Joined: 09 Jul 2005
Posts: 595
Followers: 2

Kudos [?]: 24 [0], given: 0

Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 07:25
I would vote for C. From S1 and S2 it can be determined what either x or y is (20) since median is 19. The other value can be calculated from the mean definition. Once both x and y are known the value of the range is known.
VP
VP
avatar
Joined: 22 Nov 2007
Posts: 1104
Followers: 7

Kudos [?]: 155 [0], given: 0

Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 10:35
AVakil wrote:
If Set Z has a median of 19, what is the range of Set Z?

(1) Z = {18, 28, 11, x, 15, y}

(2) The average (arithmetic mean) of Set Z is 20.


1. we have 6 numbers. the median of a set of an even number of elements is the average b/w the 3rd and the 4th. so: 11 15 18 20 28 y, in order for the median to be 19. alone is not suff

2. alone is not suff. we don't even know the number of elements in the set.

c. 20*6=120, thus we can calculate y and then the range.

OA is C
Intern
Intern
avatar
Joined: 13 Dec 2007
Posts: 29
Followers: 0

Kudos [?]: 4 [0], given: 0

Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 10:58
Answer is C
Looking at statement II (mean=20) we can rearrange first three terms of set as
{ 11,15,18._,_,_) Also,using mean value we can get
11+15+18+28+x+y/6=20
x+y=48 ...........(a)
From statement I (median=19)
18+Z/2=19.......(I used Z because this term can be either x or y)
Z=20
using equation (a) other term would be 48-20=28

now, we can complete our set as {11,15,18,20,28,28} so the range would be
28-11=17
SVP
SVP
avatar
Joined: 04 May 2006
Posts: 1937
Schools: CBS, Kellogg
Followers: 19

Kudos [?]: 375 [0], given: 1

Premium Member
Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 21:06
walker wrote:
C

1) z1={18, 28, 11, 20, 15, 20}: median=(18+20)/2=19, range=28-11=17
z2={18, 28, 11, 20, 15, 30}: median=(18+20)/2=19, range=30-11=19
insuff.

2) z1={18,20}: median=(18+20)/2=19, range=20-18=2
z2={17,21}: median=(17+21)/2=19, range=21-17=4
insuff.

1)&2). only z={18, 28, 11, 20, 15, 28} satisfies both conditions. suff.


Walker, condition 2 says nothing about median, only about mean! anyway, my vote is for C
Expert Post
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3576
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 386

Kudos [?]: 1948 [0], given: 359

GMAT ToolKit User Premium Member
Re: DS: Median and Range [#permalink] New post 14 Jan 2008, 21:23
Expert's post
sondenso wrote:
walker wrote:
C

1) z1={18, 28, 11, 20, 15, 20}: median=(18+20)/2=19, range=28-11=17
z2={18, 28, 11, 20, 15, 30}: median=(18+20)/2=19, range=30-11=19
insuff.

2) z1={18,20}: median=(18+20)/2=19, range=20-18=2
z2={17,21}: median=(17+21)/2=19, range=21-17=4
insuff.

1)&2). only z={18, 28, 11, 20, 15, 28} satisfies both conditions. suff.


Walker, condition 2 says nothing about median, only about mean! anyway, my vote is for C


ah...you are right. it should be z1={19,19,22} and z1={18,19,23} with average=20
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

SVP
SVP
avatar
Joined: 28 Dec 2005
Posts: 1586
Followers: 2

Kudos [?]: 79 [0], given: 2

Re: DS: Median and Range [#permalink] New post 15 Jan 2008, 04:47
Okay, this is what Im not getting. Just because you know the average, how do you know the order of the terms in the set that allow you to calculate the median ?
Re: DS: Median and Range   [#permalink] 15 Jan 2008, 04:47
    Similar topics Author Replies Last post
Similar
Topics:
11 Experts publish their posts in the topic Z is a set of positive numbers. The median of Z is greater goodyear2013 2 17 Jul 2014, 10:26
Experts publish their posts in the topic Z is a set of positive numbers.The median of Z is greater bagdbmba 3 07 Aug 2013, 20:49
3 Experts publish their posts in the topic If the range of the set containing the numbers x, y, and z calreg11 9 05 Feb 2012, 15:31
7 Experts publish their posts in the topic If set Z has a median of 19 , what is the range of set Z? rahularke 9 15 Sep 2009, 07:24
3 Experts publish their posts in the topic If set Z has a median of 19, what is the range of set Z? watever 8 21 Jan 2006, 00:49
Display posts from previous: Sort by

If Set Z has a median of 19, what is the range of Set Z? (1)

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.