The average velocity of the bus is 70 km/hr.
Explanation:
The average velocity of an object is ratio of net displacement to the total time taken.
Average velocity=[tex] \frac{Net displacement}{Total time taken} [/tex]
Net displacement, D = 50 + 20 = 70 km
Total time taken to cover this displacement,
T = 30 min + 15 min +30 min + 15 min = 1 hour
Substituting the values,
Average velocity= [tex] \frac{70}{1} [/tex] = 70 km/hr
