araspai wrote:

x, y and z are integers and x=y-z , x+z > x-y?

a. x is negative

b. y is negative

ANSWER E

The statement in other words is asking if z > -y

1 says that x is negative

x= y-z which says that y < z . that is .... z >y

but we do not know whether y is postive or negative

say z =-100 , y= -200

z > y , but z < -y

say z= 10 , y = 5

z> y and z> -5

so insufficient

2 says y is negative

X= Y-Z ..that is y = x + z ...here either one of them is negative or both of them is negative ...so we cant say for sure about the relationship between y and z.

say x= 100 , z =-200 ... y= -100 , z < -y

say x= -20 z =10 y = -10 , z = -y

say x= 0 , z = -1 y= -1 , z <-y

so we have no consistent solution

Combine them .... we have

x= y-z , we know x and y are negative...

we have z= y-x

y=-20 , x=-10 =>> z =-10 z <-y

y=-20 , x=-50 z = 30 z>-y

We have no consistent solution

Answer E