dreamv wrote:<-----r----- s----t-->

On the number line shown, is zero halfway between r and s?

1) s is to the right of zero
2) The distance between t and r is the same as the distance between t and -s.

IMO, Answer is C)

Does 2) mean that r=-s?

dreamv wrote:Does 2) mean that r=-s?

No, Combining 1) and 2), we can imply that r=-s
Following is my strategy
From 1)
1) s is to the right of zero.
It simply states s is positive. Nothing related to r is given. So, we can easily rule out option 1)
From 2)
2) The distance between t and r is the same as the distance between t and -s.
As nothing pertaining to signs of integers have been given here
Consider r=-4; s= -2; t=-1
distance between t and r = 3 units
distance between t and -s = 3 units
Here, 0 is not halfway between r and s

Now consider, r=-4; s=4, t=5
It will satisfy the stem of the question.
Hence, 2) alone is insufficient.

Combining 1) and 2)
s>0; t>0; r can be greater than or less than zero.
1) If r>0; there is no value of r for which statement 2) will be satisfied.
2) If r<0, the question stem will satisfy.

Hence, I went for C)
What is the OA???...and please correct me if i am wrong.

OA is C. You are correct. I never thought about z=-2, -z=2 as your example. Now I understand why the answer should be C. Thank you for your explanation.