GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 17 Oct 2018, 05:56

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

Is the range of a six-number set greater than 3?

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49969
Is the range of a six-number set greater than 3?  [#permalink]

Show Tags

New post 07 Mar 2016, 09:05
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

69% (02:01) correct 31% (02:21) wrong based on 156 sessions

HideShow timer Statistics

Is the range of a six-number set greater than 3?

(1) The sum of the five largest numbers is greater than 16.
(2) The average of the five smallest numbers is less than 2.6.

_________________

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

Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6955
Re: Is the range of a six-number set greater than 3?  [#permalink]

Show Tags

New post 08 Mar 2016, 06:53
5
7
Bunuel wrote:
Is the range of a six-number set greater than 3?

(1) The sum of the five largest numbers is greater than 16.
(2) The average of the five smallest numbers is less than 2.6.



Hi,
A good Q..

we require to know the smallest and largest number in the set to find Range..

lets see the statements:-
(1) The sum of the five largest numbers is greater than 16.
we do not know the spread if number from this..
Insuff

(2) The average of the five smallest numbers is less than 2.6
Since average is 2.6, the sum of five integers is < 5*2.6..
or Sum< 13..
we do not know the spread if number from this..
Insuff


Combined
we know sum of Largest + middle 4>16..
sum of smallest +middle 4<13
so largest -smallest >3
Suff

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

General Discussion
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6375
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: Is the range of a six-number set greater than 3?  [#permalink]

Show Tags

New post 08 Mar 2016, 17:30
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

Is the range of a six-number set greater than 3?

(1) The sum of the five largest numbers is greater than 16.
(2) The average of the five smallest numbers is less than 2.6.


In the original condition, from range=Max-min, there are 3 variables and 1 equation, which should match with the number of equations. So you need 2 more equations. For 1) 1 equation, for 2) 1 equation, which is likely to make C the answer.
When 1) & 2), they become n1+n2+n3+n4+M>16 and m+n1+n2+n3+n4<2.6*5=13. When multiplying -1 to the equation, it becomes -m-n1-n2-n3-n4>-13, which is yes and sufficient.
Therefore, the answer is C.


 For cases where we need 2 more equations, such as original conditions with “2 variables”, or “3 variables and 1 equation”, or “4 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 70% chance that C is the answer, while E has 25% chance. These two are the majority. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since C is most likely to be the answer using 1) and 2) separately according to DS definition (It saves us time). Obviously there may be cases where the answer is A, B, D or E.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Manager
avatar
S
Joined: 17 Aug 2015
Posts: 110
GMAT 1: 650 Q49 V29
Reviews Badge
Is the range of a six-number set greater than 3?  [#permalink]

Show Tags

New post 03 Nov 2016, 15:06
1
let the numbers are a, b, c,d,e, f , let's say the biggest number is a and the smallest is f so the range is f-a

1) if sum of the largest 5 integer ( b+c+d+e+f) is greater than 16, so sum of 6 integer will also be higher

a+b+c+d+e+f >16 ........................ inequality 1

2) average of the smallest 05 numbers - (a+ b+c+d+e ) /5 < 2.6

or (a+ b+c+d+e ) < 13

or -(a+ b+c+d+e ) > -13 .................inequality 2

add inequality 1 and 2

f-a > 3

so answer c
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8432
Premium Member
Re: Is the range of a six-number set greater than 3?  [#permalink]

Show Tags

New post 13 Apr 2018, 06:03
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: Is the range of a six-number set greater than 3? &nbs [#permalink] 13 Apr 2018, 06:03
Display posts from previous: Sort by

Is the range of a six-number set greater than 3?

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


Copyright

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