tejal777 wrote:
Guys,I am not understanding why you people are saying that the set consists of only 2 elements..the answer stands at C only:
eg.: {-2, -1 ,1 ,2} median=0. Is the median -ive?NO (o is neither positive nor negative)
{-3,-2,-1,2,3,4}Median=1/2.NO
{-3,-1,5,8} Median=2.NO. SUFFICIENT>C.
Please point out the flaw.
I'm not quite sure I've understood your question. But I'll try to answer it anyways.
We are looking for the median, or more specifically - We are curious if it is negative(note at this point that 0 is neither negative nor positive).
We know from the original question that there is an even ammount of elements in the set. Since we are looking for the median we and the ammount of elements is even, then we are just interested in the middle two elements.
From statement one we can draw the following conclusion:
Half of the elements are positive, which means that the other half is either negative or zero(since zero is not positive).
With this information we know that the larger one of the middle numbers is 1 or higher. Now we need to know what the lower one of the two numbers is.
Which means (1) is insufficient. As the middle of the set could look like this: {..., -10, 1, ...} making the median negative.
With statement two(2), we find out that the largest of the negative numbers is -1. (Which alone is insufficient as we don't know if there's any positive numbers at all at this point)
But combined with (1), which told us that half was positive, we can start pinpointing the lower of the two middle numbers.
Posibility one - One half is positive, the rest of the numbers are negative (which would make the -1 the lower of the middle numbers, making the median 0(Which is not negative))
Posibility two - One half is positive, the rest consists of atleast one zero and negative numbers. This would make the zero larger than -1 and therefore the number we would use when calculating the median. For example{..., 0, 1, ...} making the median 0.5.
But given a range for the two numbers that actually matters to us we can solve this question.
(1) The larger of the two elements making up the median is larger than 0(since we know it's just integers that means 1 or higher).
(2) The smaller of the two elements making up the median is either -1 or 0.
Sorry about the long post and if I'm totally off the ball. It's my first post and I'm not much of a mathematician :p
Cheers
Edit: Noticed it had several pages just now, lol. Sorry about that tejal. I'll just leave this here if anyone finds my explanation useful.