Median in a set = middle number once you have arranged the numbers from least to the highest.

-2,1,5,8 and N

The question is asking whether N is greater than zero and less than 7 or is N 1,2,3,4,5,6.

(1) Median of Set S = <5

You must remember that the median should tell you about the placement of N.
Since median is less than 5, N could be 0 and the median would still be less than 5.
OR N could be 1, and the median would still be less than 5.

Insufficient.

(1) 1< Median

This one is also insufficient.

Now, N could be 8 and the median would be greater than 1.
OR N could be something like 5 and the median would be greater than 1.


Together:

Both statements together are sufficient.
Now the median is greater than 1 and less than 5. which means the median is between these values in set s {-2,1,5,8}

In order for the median to be 2,3,4 the value of N MUST BE 0<n<7.

Does this clarify?

s consists of numbers 1, 5,-2,8 and n is 0<n<7?

1. median of numbers in s is less than 5
2. the median of numbers in s is greater than 1

1.median of numbers in s is less than 5

-2,1,n,5,8 the median is less than 5 so median may be 1 or n so n may be less than 1 and more than 1 but less than 5 so not suff. A and D out

2. median of numbers in s is greater than 1

-2,1,5,8,n
median is greater than 1 so it may be 5 ,or n so we cant say what is n not suff

B out left C n E

combine 1 n 2

median is leass than 5 n greater than 1 so -2,1 ,n,5,8 median =n so n must be more than 0 n less than 7 so suff

hence C

hope it helps