Answer :
Mass is not required
- Time=12h
- Displacement=600km
[tex]\\ \sf\longmapsto Average\:Velocity=\dfrac{Total\:Displacement}{Total\:Time}[/tex]
[tex]\\ \sf\longmapsto Average\:Velocity=\dfrac{600}{12}[/tex]
[tex]\\ \sf\longmapsto Average\:Velocity=50km/h[/tex]