sanju09 wrote:Is x + y positive?

(1) x - y is positive.

(2) y - x is negative.

IMO E

Qn: is x + y > 0?

1. x - y > 0

X = 1, y = 1 suffice

x = 1, y = -1 insuffice

2. Same can be applied so insuffice. Identical to 1.

If one statement is insuffice, thus both are insufficient.

Choose E.

Can anyone advise if we can add the 2 inequalities instead of picking numbers?

dxgamez wrote:Qn: is x + y > 0?

1. x - y > 0

X = 1, y = 1 suffice

x = 1, y = -1 insuffice

2. Same can be applied so insuffice. Identical to 1.

If one statement is insuffice, thus both are insufficient.

Choose E.

Can anyone advise if we can add the 2 inequalities instead of picking numbers?

You neither need to add inequalities nor to pick numbers here. Apply the basic number properties to get any credit in the given case. The number picking policy used in your explanation is even not clear to me. You didn't mention why it's so that "If one statement is insuffice, thus both are insufficient."

Sorry about the unclear explanation. Happens when you try to do everything in your mobile

Let me re-explain:-

st 1:- x - y > 0

Pick some numbers that satisfy st 1:-

x= 2, y = 1 ---- this shows that x+y is +ve, thus suffice cos qn stem is asking if x+y >0.

x = 1, y = -1 ---- this shows that x+y is equal to 0, thus insuffice cos doesnt satisfy qn stem.

thus, st 1 is insufficient.

st 2:- y-x < 0

multiplying (-) both sides gives x - y > 0, which is the same expression as st 1, thus insufficient.

@sanju09, you mentioned that "You neither need to add inequalities nor to pick numbers here. Apply the basic number properties to get any credit.."

could you show how to apply the basic number properties?

This is my thinking:-

1. simplify qn stem x > - y

2. st 1 & st 2 show that x > y

3. thus insufficient...

is this right?

Both statements are same.

When x - y > 0, x > y, or x and y are different valued numbers whose sum could be anything, positive, negative, or zero. Hence, each of the identical statement is insufficient.

[spoiler]E[/spoiler]

Inequalities:

(1) x-y > 0

(2) y-x < 0 =!= 0 < x-y OR x-y > 0

as sanju09 said, they are the same

test:
x=1 y=-2 => 1-(-2)=3, thus statements hold, and x+y=-1 (neg)
but statements also hold when x=2 y=1, and X+y=3 (pos)

thus you can't say whether they are + or -
ANSWER: E