A boat goes 20 km upstream and returns in 6 hours. If the speed of the boat in still water is 7.5 km/hr, what is the speed of the stream?
1
2 km/hr
2
2.5 km/hr
3
4 km/hr
4
4.5 km/hr
5
6 km/hr
A boat goes 20 km upstream and returns in 6 hours. If the speed of the boat in still water is 7.5 km/hr, what is the speed of the stream?