It is currently 21 Oct 2017, 20:15

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If X is a set of four numbers, a, b, c, and d, is the range of the num

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 41892

Kudos [?]: 129181 [0], given: 12194

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
Expert's post
2
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

61% (00:37) correct 39% (00:32) wrong based on 106 sessions

### HideShow timer Statistics

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.
[Reveal] Spoiler: OA

_________________

Kudos [?]: 129181 [0], given: 12194

Senior Manager
Joined: 27 Oct 2013
Posts: 253

Kudos [?]: 128 [0], given: 79

Location: India
Concentration: General Management, Technology
GMAT Date: 03-02-2015
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

Kudos [?]: 128 [0], given: 79

Manager
Joined: 22 Oct 2014
Posts: 88

Kudos [?]: 72 [1], given: 4

Concentration: General Management, Sustainability
GMAT 1: 770 Q50 V45
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
1
KUDOS
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.

_________________

$$\sqrt{-1}$$ $$2^3$$ $$\Sigma$$ $$\pi$$ ... and it was delicious!

Please consider giving +1 Kudos if deserved!

Kudos [?]: 72 [1], given: 4

Intern
Joined: 21 Jul 2013
Posts: 14

Kudos [?]: 2 [1], given: 20

Location: Moldova, Republic of
GMAT 1: 610 Q47 V28
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
1
KUDOS

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

Kudos [?]: 2 [1], given: 20

Current Student
Joined: 03 Oct 2014
Posts: 145

Kudos [?]: 37 [1], given: 89

Location: India
Concentration: Operations, Technology
GMAT 1: 720 Q48 V40
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
1
KUDOS
My 2 Cents on B !!!! Clearly A-B>4....sufficient enough to tell range atleast 4

Kudos [?]: 37 [1], given: 89

Manager
Joined: 23 Oct 2014
Posts: 103

Kudos [?]: 57 [0], given: 66

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. a-d>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, a-d>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 a-d, 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.

Kudos [?]: 57 [0], given: 66

Manager
Joined: 22 Oct 2014
Posts: 88

Kudos [?]: 72 [0], given: 4

Concentration: General Management, Sustainability
GMAT 1: 770 Q50 V45
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!

Kudos [?]: 72 [0], given: 4

Math Expert
Joined: 02 Sep 2009
Posts: 41892

Kudos [?]: 129181 [0], given: 12194

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.
_________________

Kudos [?]: 129181 [0], given: 12194

Math Expert
Joined: 02 Sep 2009
Posts: 41892

Kudos [?]: 129181 [0], given: 12194

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: if-s-is-a-set-of-four-numbers-w-x-y-and-z-is-the-range-o-166184.html
_________________

Kudos [?]: 129181 [0], given: 12194

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16589

Kudos [?]: 273 [0], given: 0

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.
_________________

Kudos [?]: 273 [0], given: 0

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
Display posts from previous: Sort by