Aman travels a distance of 48 km from Agra to Bhopal with a speed of 4 km/hr and also travels a distance of 54 km from Bhopal to Chennai with a speed of 6 km/hr. Find the average speed of the whole journey?
1
6 km/hr
2
106/21 km/hr
3
102/21 km/hr
4
7 km/hr