Data Sufficiency

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

(1) x and y are prime nos.
(2) y > 7

OA C

here you go.

x(y+1) will be even under the following conditions :

x - even (y+1)- even
x - odd (y+1)- even
x - even (y+1)- odd

Now from statement 1

x and y are prime numbers
you could pick 2,3 = 2(4) = 8 even
or you could pick 3,2 = 3(3) = 9 odd
Therefore statment 1 is insufficient

From statement 2

It states that Y>7
again you could pick
any 2 numbers for x and y and the product could be even or odd

If you combine the 2 statments,

X and y are prime and y>7.
We know that 2 is the only even prime number and all other prime numbers are odd.
Therefore y+1 will always be even and hence the product x(y+1) will be even whether x is even or odd.

Hope this helps