Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 46166

If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
12 Jan 2015, 11:07
Question Stats:
63% (00:39) correct 37% (00:34) wrong based on 115 sessions
HideShow timer Statistics



Manager
Joined: 27 Oct 2013
Posts: 238
Location: India
Concentration: General Management, Technology
GMAT Date: 03022015
GPA: 3.88

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
12 Jan 2015, 23:20
here we go.
St1: a is the greatest number in X
Clearly Insufficient
St2: a – d > 4
No information is given about b and c Clearly Insufficient
Combining 
a is the greatest number in X, and a – d > 4 > a > d+4
If d is the minimum value in X, avg has to be greater than 4 (already given)
And If b or c has the minimum value (a being the greatest), b/c will be less than d (in that case) > and that will automatically give Range greater than 4.
According to me Option C is the correct answer



Manager
Joined: 22 Oct 2014
Posts: 88
Concentration: General Management, Sustainability
GPA: 3.8
WE: General Management (Consulting)

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
12 Jan 2015, 23:31
Statement 1: In deed clearly insufficient as we are given no information about the difference off the numbers. Statement 2: Sufficient. Even if a is not the largest number our be is not the smallest, there difference is larger than 4, so the range of the entire set cannot be smaller than 4. If the other two numbers are further apart, that only increases the range. Answer B.
_________________
\(\sqrt{1}\) \(2^3\) \(\Sigma\) \(\pi\) ... and it was delicious!
Please consider giving +1 Kudos if deserved!



Intern
Joined: 21 Jul 2013
Posts: 13
Location: Moldova, Republic of
GPA: 3.62

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
13 Jan 2015, 12:16
My answer is B.
If we have the difference of any two numbers in the set X greater than 4, the range will be at least equal to that difference, so it will be as well greater than 4



Manager
Joined: 03 Oct 2014
Posts: 138
Location: India
Concentration: Operations, Technology
WE: Engineering (Aerospace and Defense)

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
13 Jan 2015, 12:35
My 2 Cents on B !!!! Clearly AB>4....sufficient enough to tell range atleast 4



Manager
Joined: 23 Oct 2014
Posts: 98
Concentration: Marketing

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
13 Jan 2015, 12:52
Bunuel wrote: If X is a set of four numbers, a, b, c, and d, is the range of the numbers in X greater than 4?
(1) a is the greatest number in X (2) a – d > 4
Kudos for a correct solution. I want to pick C. 1. a is the greatest number in X. This info is insufficient as it tells us nothing about the value of a or what the other variables are. 2. ad>4 This info is also insufficient as we still don't know what the other variables are. Together: Since we know that a is the greatest number in the set, ad>4 tells us that (The greatest value)  d > 4. Even if d is not the smallest number to give us the range of set X we know that the range has to be greater than ad, which is much greater than 4. If d is the smallest value of the set then the range surely has to be be greater than 4. So together we can only assume that the range must be greater than 4.



Manager
Joined: 22 Oct 2014
Posts: 88
Concentration: General Management, Sustainability
GPA: 3.8
WE: General Management (Consulting)

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
13 Jan 2015, 13:32
It still should be B. Even if a is not the greatest number of all, still the range is at least 5. If b or c are even greater than a, the range will be greater accordingly.
_________________
\(\sqrt{1}\) \(2^3\) \(\Sigma\) \(\pi\) ... and it was delicious!
Please consider giving +1 Kudos if deserved!



Math Expert
Joined: 02 Sep 2009
Posts: 46166

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
19 Jan 2015, 03:53
Bunuel wrote: If X is a set of four numbers, a, b, c, and d, is the range of the numbers in X greater than 4?
(1) a is the greatest number in X (2) a – d > 4
Kudos for a correct solution. OFFICIAL SOLUTION:To solve this problem, you have to be able to say with certainty that the range is greater than 4. range = largest value – smallest value Statement (1) tells you nothing to help you determine the range. It tells you which variable is largest, but you don’t know its value or the value of the lowest variable. Statement (1) isn’t sufficient, so the answer isn’t A or D. Statement (2) tells you that the difference between two of the values, d and a, is more than 4. This is helpful because if any of the two numbers in the set have a difference of more than 4, the range, at the very least, has to be greater than 4. Statement (2) is sufficient, and you can eliminate C and E. Choose B.
_________________
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? Extrahard Quant Tests with Brilliant Analytics



Math Expert
Joined: 02 Sep 2009
Posts: 46166

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
19 Jan 2015, 03:53
Bunuel wrote: Bunuel wrote: If X is a set of four numbers, a, b, c, and d, is the range of the numbers in X greater than 4?
(1) a is the greatest number in X (2) a – d > 4
Kudos for a correct solution. OFFICIAL SOLUTION:To solve this problem, you have to be able to say with certainty that the range is greater than 4. range = largest value – smallest value Statement (1) tells you nothing to help you determine the range. It tells you which variable is largest, but you don’t know its value or the value of the lowest variable. Statement (1) isn’t sufficient, so the answer isn’t A or D. Statement (2) tells you that the difference between two of the values, d and a, is more than 4. This is helpful because if any of the two numbers in the set have a difference of more than 4, the range, at the very least, has to be greater than 4. Statement (2) is sufficient, and you can eliminate C and E. Choose B. Similar question to practice: ifsisasetoffournumberswxyandzistherangeo166184.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? Extrahard Quant Tests with Brilliant Analytics



NonHuman User
Joined: 09 Sep 2013
Posts: 7005

Re: If X is a set of four numbers, a, b, c, and d, is the range of the num [#permalink]
Show Tags
11 Sep 2017, 04:56
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




Re: If X is a set of four numbers, a, b, c, and d, is the range of the num
[#permalink]
11 Sep 2017, 04:56






