Bunuel wrote:

Is x an even integer? Assume n and p are integers.

(1) x = (n + p)^2

(2) x = 2n + 10p

St 1, if n+p=odd number, then x will be odd, but if n+p is even, then it'll be even. We don't know if n or p are even or odd.

St 2, an even number times any integer will be even. Therefore 2n is even and 10p is even. Even + even = even. Sufficient.

_________________

I'd love to hear any feedback or ways to improve my problem solving. I make a lot of silly mistakes. If you've had luck improving on stupid mistakes, I'd love to hear how you did it.

Also, I appreciate any kudos.