Well [tex]s=\dfrac{d}{t}[/tex] where s is speed, d is distance and t is time.
We have distance and time so we can calculate speed.
[tex]s=\dfrac{24}{37\cdot10^{-9}}\approx6.5\cdot10^8\frac{\mathbf{m}}{\mathbf{s}}\approx\boxed{6.5\cdot10^2\frac{\mathbf{Mm}}{\mathbf{s}}}[/tex]
Hope this helps.
r3t40