Data Sufficiency

If xy not equal to 0, is (x/y) <0?

1. x=-y

2. -x=-(-y)

qa is d


I rephrased this down to is x<y

which led me to qa of E since both statement are the same.

lets shed some light on this!

Simbu,
Either one is sufficient because if u consider 1 as postive the ithe rone will be negative.

Stmt I

xy <> 0
x=-y


Let y=2 x=-2 x/y <0
y=-2 x=2 x/y<0

SUFF

Stmt II

-x=y

Let x=2 y=-2 x/y <0
x=-2 y =2 x/y < 0

SUFF

Either x or y will be negative based on conditions so x/y < 0

D)

Simbu,
Either one is sufficient because if u consider 1 as postive the OTHER one will be negative.

Stmt I

xy <> 0
x=-y


Let y=2 x=-2 x/y <0
y=-2 x=2 x/y<0

SUFF

Stmt II

-x=y

Let x=2 y=-2 x/y <0
x=-2 y =2 x/y < 0

SUFF

Either x or y will be negative based on conditions so x/y < 0

D)

My question to this simple yet roadblock question is, did I rephrase in a wrong manner?

WHen rephrased statements 1 and 2 have no effect of sufficiency. BUt if left alone then its crystal clear that answer is d.

Whats up?

In a way yes.

x/y<0 is not the same as x<y

I have been running through many inequalities and saw that I was getting slapped around by many of these questions. I like to plug in numbers but am realizing that i need to take a more theoretical and algebraic approach. I know for sure that rephrasing was a big issue for me. I made a violation in the beginning of the question.

If you notice, I rephrased is (x/y)<0 to is x<y by moving the y over to the other side. THis has caused me many problems and I am making a huge takeaway here and hope the community here can learn also. Be careful when reohrasing inequalities.

Crystal clear now!

simba,

here's another approach....
given xy <>0
and also in 1.) x = -y
we are asked to find is x/y < 0?..... I
plug x = -y in I
-1 < 0 , yes. so suff
2.) gives -x = y which is just a rephrase of the 1.) choice.
so both are suff on their own.... so ans is D
hope it helps....