Answer:
The velocity of the bus be is 0 miles/second
Step-by-step explanation:
Given, a bus travelled a distance of 20 miles north and 20 miles back to the starting point
Hence, total distance = 20 + 20 = 40 miles
Velocity is calculated by the formula:
Velocity =

Displacement =

Velocity =

Therefore, the velocity of the bus is 0 miles/second