Prelims 2026 · CSAT / Quantitative Aptitude · Question 3
If x and y are integers, then is x even?<br/>Statement I :<br/>x^2 y^2 is even.<br/>Statement II :<br/>1 + x^2 + y^2 is odd.<br/>
Answer
Select this option if the question can be answered using both the statements together, but cannot be answered using either statement alone
Statement I: x^2y^2 is even, so at least one of x,y is even. x need not be even. Not sufficient.
Statement II: 1+x^2+y^2 is odd, so x^2+y^2 is even. Hence x and y have the same parity: both even or both odd. x need not be even. Not sufficient.
Together: at least one is even, and both have same parity. Therefore both must be even. So x is definitely even.