A man travels 40 km at speed 20 km/h and next 60 km at 20 km/h and there after travel 40 km at 40 km/h. His approx. average speed is
1
15
2
20
3
30
4
23
A man travels 40 km at speed 20 km/h and next 60 km at 20 km/h and there after travel 40 km at 40 km/h. His approx. average speed is