Answer : 0.093 m/s
Explanation :
Average velocity is calculated using displacement of the object.
Hence average velocity = displacement/time
Since displacement is a vector, direction is necessary.
Distance walked towards east = 273 m
Distance walked towards west = 581 m
Since the direction is opposite, displacement = 273 + (-581) = -308 towards east = 308 towards west
Average velocity = displacement/time = 308 m/ (55*60) sec = 308/3300 = 0.093 m/s due west