List A consists of five distinct integers. Is the range of t

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List A consists of five distinct integers. Is the range of the numbers in list A greater than 8?

(1) List A does not contain a multiple of 5.
(2) No two numbers in list A are consecutive.

What's the best way to verify which statement is sufficient? Can any experts help?

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by GMATGuruNY » Mon Dec 04, 2017 7:46 pm
ardz24 wrote:List A consists of five distinct integers. Is the range of the numbers in list A greater than 8?

(1) List A does not contain a multiple of 5.
(2) No two numbers in list A are consecutive.
Statement 1:
Case 1: 1, 2, 3, 4, 6.
In this case, the range = 6-1 = 5, so the answer to the question stem is NO.
Case 2: 1, 2, 3, 4, 11.
In this case, the range = 11-1 = 10, so the answer to the question stem is YES.
Since the answer is NO in Case 1 but YES in Case 2, INSUFFICIENT.

Statement 2:
Case 1: 1, 3, 5, 7, 9
In this case, the range = 9-1 = 8, so the answer to the question stem is NO.
Case 2: 1, 3, 5, 7, 10.
In this case, the range = 10-1 = 9, so the answer to the question stem is YES.
Since the answer is NO in Case 1 but YES in Case 2, INSUFFICIENT.

Statements combined:
Counting up from 1, the smallest possible ranges are yielded by the following cases:
1, 3, 7, 9, 11 --> range is 10
2, 4, 6, 8, 11 --> range is 9
3, 7, 9, 11, 13 --> range is 10
4, 6, 8, 11, 13 --> range is 9
The cases above illustrate that the smallest possible range is 9.
Thus, the answer to the question stem is YES.

The correct answer is C.
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