A man has to cover a distance of 40 kms. He walks 16 kms at the speed of 4 km/hr and the rest is covered by Tonga. If he had covered 16 kms by Tonga and the rest by walking at the speed of 4 km/hr, then he would have taken 1 hour more. Find the speed of Tonga.
1
16 km/h
2
8 km/h
3
12 km/h
4
10 km/h