X & Y as integers

[relaxin99]

If x & y are integers, is the value of x(y + 1) even?

(1) x & y are prime numbers
(2) y > 7




The answer is C, can someone please explain why

[cramya]

X(Y+1) = XY+X


Stmt I

x and y are prime numbers.

If x and y are both 2 then we get an even result
If x is even, y is odd we get an odd result
INSUFF

Stmt II

y>7

No info about x
Could be even or odd


Together

Since y>7 y is always odd

When x is odd

xy+x = odd*odd + odd
=even

When x is even
xy+x = even*odd+even
= even

SUFF

Choose C

Regards,
CR

[logitech]

All primes , but 2 , are ODD

ODD(ODD+1) = EVEN

But if one of them is 2

2(ODD+1) = EVEN
ODD(2+1) = ODD
2(2+1) = EVEN

so if we know that Y is not 2 we can solve the problem.
'
Choose C

[x2suresh]

agree with C