Hey guys I got the answer buthave a querie.
Basically the question is asking us is y<0 ???
The first statement tells us y<2,which should be insufficient..but but..! if y=0 or 1 if we apply these values to the equation,it won't result in less than 10.So for this reason y should be -ive..
Is this correct?

The initial statement:
x-y>10 can be broken down to x>10+y
We're asked to find, is x-y>x+y?
Or...
Substituting in, (10+y)-y>(10+y)+y
10>10+2y
0>y

So, we know that with our initially given truth, the question asked can only be true when y<0.

(1) x=8
So, 8>10+y
-2>y
Sufficient. As we proved above that y must be less than 0. From statement 1, we know that y is less than -2.

(2) y=-20
Sufficient. y=-20 is certainly less than 0.

D.

PS: I think you just miscalculated what you were looking at (with y<2 instead of y<-2).

sorry sleep deprived..forgot the minus :(