IMO E.

Just try different numbers

x = 21 y = -2

x = 19 y = 1

You can't subtract inequalities, only add them.

Oops

In second example x would have to be 18 so x + y is less than 20, but you get the point.

Ian Stewart wrote:You can add two inequalities, but you can't subtract them. Take an example of two inequalities which are true, and subtract:

2 > 1
2 > 0
0 > 1

which is clearly false.

In the question above, x could be 30 and y could be -11, or x could be 10 and y could be 9, so the answer is E.

Just adding something to it.
You can always subtract a constant from the both sides of an equality.

[quote="Ian Stewart"][b]You can add two inequalities, but you can't subtract them. Take an example of two inequalities which are true, and subtract:[/b]
2 > 1
[u]2 > 0 [/u]
0 > 1

which is clearly false.

In the question above, x could be 30 and y could be -11, or x could be 10 and y could be 9, so the answer is E.[/quote]

Thanks Ian and Mike for pointing it to me...Inequalities always come up with revelations.....