meraGMAT1 wrote:Is x-y > r-s?
(1) x > r and y < s
(2) y = 2, s = 3, r = 5, and x = 6
OA is (D)
My question is:
Subtracting 2 inequalities is WRONG.

Then how is OA (D)
That is:
(1) x > r and y < s?
should not mean
x-y > r-s
Any ideas?
Thanks

First, it's useful to recognize that if a>b, then a-b>0 (or a-b is positive)

For this question, it helps to rearrange the terms in the initial question:
If we take "Is x-y > r-s?" and subtract r from both sides and add s to both sides we get
"Is x-y-r+s > 0?" We can rearrange the terms to get
"Is (x-r)+(s-y) >0?"

Statement (1): x > r and y < s
This tells us that x-r is positive and s-y is positive
So, the question "(x-r)+(s-y) >0?" can now be answered since we know that x-r and s-y must both be positive.
SUFFICIENT

Statement (2) is sufficient since we are given the values of all 4 variables.