Data Sufficiency

prat_agl wrote:if x and y are positive, is x<10<y?
1) x<y and xy<100
2) x^2 < 100 < y^2

I got A as the answer but OA is D. How can B give the correct ans. What if x= -11. This will not satisfy x^2 <100 but it will satisfy x < 10. Please help.

I think the first statement is: x < y and xy = 100

(1) x < y and xy = 100
It is given that both x and y are positive and x < y. So, for xy = 100 to be true, one multiple should be < 10 and the other should be > 10.
Therefore, x < 10 < y; SUFFICIENT.

(2) x² < 100 < y²
Taking square root, we get, |x| < 10 < |y|
Since x and y are positive, so x < 10 < y; SUFFICIENT.

The correct answer is D.