see below

Hi Makushr1,

The best way to attack this question is through plugging in numbers. This is a VALUE question, which means that a statement or combination of statements is sufficient only if you can find ONE SINGLE VALUE.

For this reason, all you need to do is find two possible values in order to render a statement insufficient.

(1) 4 is the integer that is closest to x+y

Two possibilities are x=3.5 y=0.5 (in which case x is closest to 4) and x=2.5 y=1.5 (in which case x is closest to 3).

INSUFFICIENT

(2) 1 is the integer that is closest to x-y

Two possibilities are x=3.5 y=2.5 and x=2.5 y=1.5

INSUFFICIENT (for the same reason)

For (1) and (2) together, you could have x=2.5 y=1.5 (in which case x is closest to 3), but you could also have x=2.4 y=1.4 (in which case x is closest to 2).

That's all you need!

Final answer E

1) 4 is the integer that is closest to x+y
2) 1 is the integer that is closest to x-y

Could you do this?

x+y=4
x-y=1
2x=5
x=2.5

Since X is between two numbers and the initial equation values were estimated, X could be a little up or a little down making it close to either 3 or 2.