What is the value of x?

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What is the value of x?

by M7MBA » Sun Dec 10, 2017 10:40 am
What is the value of x?

(1) The median of set (x, 1, -1, 3, -x) is 0
(2) The median of set (x, 1, -1, 3, -x) is x/2

The OA is A.

Why is the statement (2) not sufficient? Experts, may you help me here? I don't have it clear.

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by DavidG@VeritasPrep » Sun Dec 10, 2017 10:49 am
M7MBA wrote:What is the value of x?

(1) The median of set (x, 1, -1, 3, -x) is 0
(2) The median of set (x, 1, -1, 3, -x) is x/2

The OA is A.

Why is the statement (2) not sufficient? Experts, may you help me here? I don't have it clear.
Statement 1: Notice that there are 5 elements in the set. Because there are an odd number of elements, the median must be in the set. (If there had been an even number of elements the median would be the average of the two middle terms.) The only way the median of the set can be 0 is if x = 0. Because there is a unique value for x, this statement alone is sufficient.

Statement 2:
Case 1: x = 0. (Meaning -x = 0 and x/2 = 0/2) Our set is (-1, 0, 0, 1, 3.) The median is 0, which is also x/2 or 0/2.
Case 2: x = 2. (Meaning -x = -2 and x/2 = 1.) Now our set is (-2, -1, 1, 2, 3). The median is 1, which is also x/2 or 2/2.
Because x can assume multiple values, this statement alone is not sufficient.

The answer is A
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