If $2^{n}=8^{20}$, what is the value of $n$ ?
(A) 10
(B) 60
(C) 40
(D) 16
(E) 17
Since $8=2 \times 2 \times 2=2^{3}$, then $8^{20}=\left(2^{3}\right)^{20}=2^{3 \times 20}=2^{60}$.

Thus, if $2^{n}=8^{20}$, then $n=60$.

ANsWER: (B)