vscid wrote:If x, y, z are integers, is x(y^2 + z^3) even?

1] x is odd.
2] The product xyz is odd.

Question stem: if x(y^2 + z^3) is even

either x is even and y can be either even or odd or z could be either even or odd, or all x y & z are odd.

Statement I
x is odd, we dont know anything y or z

if x is odd, y and z are also odd, then entire expression is even, because odd+odd = even

if y is even and z is odd or vice versa, then odd+even = odd, the entire expression becomes odd.

Insufficient.

Statement II

xyz = odd

this means x is odd, y is odd & z is odd

odd ( odd+odd) = odd* even = even, since odd+odd = even

Sufficient.

Hence, B.