Is xy > 0 ?
(1) x - y > -2
(2) x - 2y < -6
vivekcall81 Wrote:C cannot be the answer if you x=3 and y=5
yes XY>0 but out it in to the equation
x-y=3-5=-2 which is equal but not .-2
hence not satisfied and E should be the answer.
Vivek,
Given (1) and (2), we have to see whether xy>0.
Now x=3, y=5
x-y=-2, which means that (1) itself is not satisfied. so you cannot take this pair at all.
jigar24 Wrote:Hi Ron, but could you be more clear on how to eliminate 'B' first?.. I am able to eliminate 'A' (and so also 'D') easily but getting stuck on eliminating 'B' (only statement 2 alone is sufficient).
Thanks
My approach:
In order for xy>0 both x and y either have to positive or both negative.. So, I tired to come up with  numbers 1) both with same signs  2) Both with different signs .. if both these type work in a statement then it implies given statement is NOT sufficient..Â
In the process, I could very easily prove statement 1 insufficient but  getting stuck (and taking an eternity) on statement 2 ... cant come up with examples fast enough..
Please help
jigar24 Wrote:Ron, I understood the first part that you mentioned.. That will surely make life much easier.. One has to try to get +ve value on the right hand side of '<' sign and a -ve value on the right hand side of '>' sign, in order to include all three signs and prove the statement insufficient.. Right??
However, I am still a bit unclear about your second explanation:
"alternatively, if you don't think of solving the original inequality for x, just find a solution in which both numbers are positive (say, 10 and 10), and then realize that you can just make one of the numbers 0. that's good enough, since 0 > 0 is false."
Could you please explain this once more, with an example??