If $512^{x}=64^{240}$, then $x$ equals
(A) 80
(B) 30
(C) 360
(D) 160
(E) 237
We note that $64=2^{6}$ and $512=2^{9}$.

Therefore, the equation $512^{x}=64^{240}$ can be rewritten as $\left(2^{9}\right)^{x}=\left(2^{6}\right)^{240}$ or $2^{9 x}=2^{6(240)}$.

Since the bases in this last equation are equal, then the exponents are equal, so $9 x=6(240)$ or $x=\frac{1440}{9}=160$.

ANSWER: (D)