Answer
$3.00\times10^{8}~m/s=6.71\times10^{8}~mi/h$
Work Step by Step
See conversion factors (inside front cover).
$1~mi=1609~m$ and $1~h=3600~s$
$3.00\times10^{8}~m/s=(3.00\times10^{8}~m/s)(\frac{1~mi}{1609~m})(\frac{3600~s}{1~h})=6.71\times10^{8}~mi/h$
