Brad is incorrect.
0.05 k m  =  0.05  ⋅  1000 m  =  50 m
s  =  d/ t
where  d  is distance in metres  (m) ,
and t is time in seconds.
and s is speed in meters per second m/s
d  =  50 m  and  t  =  10 s
50m/10s
s = 5 m/s
Brad did most everything correctly just that the number would need to be multiplied by  1000  since the unit  k m  was converted to  m .