Data Sufficiency

lenagmat wrote:Is (X^2+Y^2) a square of an integer?

1). x is even, y is odd
2). x and y are odd

(1) x is even, y is odd.
If x = -2 and y = 5, then x² + y² = 4 + 25 = 29, which is not the square of an integer.
If x = 4 and y = 3, then x² + y² = 16 + 9 = 25, which is the square of an integer.
We do not get a definite answer; NOT sufficient.

(2) x and y are odd.
If x = 1 and y = 3, then x² + y² = 1 + 9 = 10, which is not the square of an integer.
If x = 3 and y = 5, then x² + y² = 9 + 25 = 34, which is not the square of an integer.
So, x² + y² is not the square of an integer; SUFFICIENT.

The correct answer is B.