If $x=2t$ and $y=\frac{t}{3}$, what is the value of $x^2-y^2$?
(1) $t^2-3=6$
(2) $t^3=-27$

The correct option is D Each statement alone is sufficient.
This problem can be solved by determining the value of , and this can be determined if the value of or the value of can be determined. From statement 1, it indicates that and so . Thus, statement 1 is sufficient. From statement 2, it indicates that and so . Thus, statement 2 is sufficient.