Answer
6
Work Step by Step
For any positive real number $b$ (such that $b\ne1$), we know that $log_{b}b^{r}=r$ (as long as $r\gt0$).
For $log_{2}64$:
We know that $2^{6}=64$, so we can replace 64 with $2^{6}$.
Therefore, $log_{2}64=log_{2}2^{6}=6$.
