It is currently 22 Oct 2017, 19:56

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

M14 #5

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
1 KUDOS received
Forum Moderator
Forum Moderator
User avatar
Status: mission completed!
Joined: 02 Jul 2009
Posts: 1391

Kudos [?]: 953 [1], given: 621

GPA: 3.77
GMAT ToolKit User Premium Member Reviews Badge
M14 #5 [#permalink]

Show Tags

New post 04 Nov 2010, 11:57
1
This post received
KUDOS
If set consists of even number of integers, is the median of set negative?

Exactly half of all elements of set are positive.
The largest negative element of set is -1.

[Reveal] Spoiler:
С


I found the most efficient way to solve this question.

Is is asked whether the median is negative? for sufficiency we have to demonstrate one Yes and one No.

lets say that in S are 4 numbers, \(A1, A2, A3, A4\). and median is equal to \((A2+A3)/2\) - for this to be negative, absolute value of A2 must be grater than A3. |A2|>|A3|. you need to check whether it |A2|>|A3| is always true or false.

1)Exactly half of all elements of set are positive.
Remember here that 0 is neither positive nor negative.
For insuficiency we need to find this |A2|>|A3| to be true and false.
True |A2|>|A3|, S {-2;-2;1;2}, |-2|>|1|
False |A2|>|A3|, S {-2;0;1;2}, |0|<|1|

2)The largest negative element of set is -1.
True |A2|>|A3|, {-2;-1;0;0} |-1|>|0|
False |A2|>|A3, false {-2;-1;3;4} , |-1|<|3|

1)&2) two positive elements and the largest negative integer is -1
so {-3;-1;1;2}, because the second number must be -1 and the smallest postitive out of two is 1, thus (-1+1)/2=0 - which is not negative , for other cases when third element is grater than 1, answer is NO, not negative (-1+4)/2=positive.
_________________

Audaces fortuna juvat!

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 953 [1], given: 621

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41912

Kudos [?]: 129370 [0], given: 12197

Re: M14 #5 [#permalink]

Show Tags

New post 04 Nov 2010, 19:33
Pkit wrote:
If set consists of even number of integers, is the median of set negative?

Exactly half of all elements of set are positive.
The largest negative element of set is -1.

[Reveal] Spoiler:
С


I found the most efficient way to solve this question.

Is is asked whether the median is negative? for sufficiency we have to demonstrate one Yes and one No.

lets say that in S are 4 numbers, \(A1, A2, A3, A4\). and median is equal to \((A2+A3)/2\) - for this to be negative, absolute value of A2 must be grater than A3. |A2|>|A3|. you need to check whether it |A2|>|A3| is always true or false.

1)Exactly half of all elements of set are positive.
Remember here that 0 is neither positive nor negative.
For insuficiency we need to find this |A2|>|A3| to be true and false.
True |A2|>|A3|, S {-2;-2;1;2}, |-2|>|1|
False |A2|>|A3|, S {-2;0;1;2}, |0|<|1|

2)The largest negative element of set is -1.
True |A2|>|A3|, {-2;-1;0;0} |-1|>|0|
False |A2|>|A3, false {-2;-1;3;4} , |-1|<|3|

1)&2) two positive elements and the largest negative integer is -1
so {-3;-1;1;2}, because the second number must be -1 and the smallest postitive out of two is 1, thus (-1+1)/2=0 - which is not negative , for other cases when third element is grater than 1, answer is NO, not negative (-1+4)/2=positive.


Also discussed here: ds-set-14343.html
_________________

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 [?]: 129370 [0], given: 12197

Re: M14 #5   [#permalink] 04 Nov 2010, 19:33
Display posts from previous: Sort by

M14 #5

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

Moderator: Bunuel



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®.