Bunuel
If x and y are positive integers, is x^2 + y^2 + 2 divisible by 6?
(1) xy is even
(2) x is odd
For x^2 + y^2 + 2 to be divisible by 6, x^2 + y^2 + 2 should be even.
Statement 1(1) xy is evenCase 1: x = 6, y = 4
x^2 + y^2 + 2 = 36 + 16 + 2 = 54
Is 54 divisible by 6 - Yes!
Case 2: x = 1, y = 4
x^2 + y^2 + 2 = 1 + 16 + 2 = 19
Is 19 divisible by 6 - No!
As we are getting multiple answers to the question, the statement alone is not sufficient.
We can eliminate A and D.
Statement 2(2) x is oddCase 1: x = 1, y = 3
x^2 + y^2 + 2 = 1 + 9 + 2 = 12
Is 12 divisible by 6 - Yes!
Case 2: x = 1, y = 4
x^2 + y^2 + 2 = 1 + 16 + 2 = 19
Is 19 divisible by 6 - No!
As we are getting multiple answers to the question, the statement alone is not sufficient.
We can eliminate B.
Combined Combined, x is odd and y is even.
In that case, x^2 + y^2 + 2 = odd.
Is x^2 + y^2 + 2 divisible by 6? - No !
We have a definite answer to the question. Hence, we can answer the question when the statements are taken combined.
Option C