XY Question

[Spartacus2000]

If wx = y, what is the value of xy?

(1) wx^2 = 16

(2) y = 4

Thanks.

[ColumbiaVC]

A

Given wx=y and xy=?
1) w(x^2)=16
=> wx(x)=16 substitute wx=y
=> y(x)=16
=> xy=16
Sufficent

2) y=4
Don't know the value of x. So, can't find xy value.
Not Sufficient