The speed of a boat in still water 11 km/hr. It can go 12 km upstream and return downstream to the engine point in 2hr 45min. What is the speed of stream?

A motorboat can travel at 10 km/hr. in still water it travelled 91 km downstream in a river and then returned taking at together 20 hours. Find the rate of flow of the river 

A person swims a distance of 28 km. in the direction of stream in 5 hours and a distance of 13 km. in 5 hours against the stream. What is the velocity of the stream?

A man can row 30 km upstream and 44 km downstream in 10 hours. Also, he can row 40 km upstream and 55 km downstream in 13 hours. The rate of the current is – 

Speed of a boat in still water is 6 km/hr and speed of the current is 2 km/hr. If boat takes four hours more in upstream than in the downstream to cover ‘D’ km, then find time take by boat to cover ‘D’ km in still water?

A boat travel 240 km downstream in 3 hours and the time is taken by the boat to travel the same distance in upstream in 6 hours. Find the speed of stream (in kmph).

A boat goes 10kms an hour in still water, but takes twice as much time in going the same distance against the current. The speed of the current (in km/hr) is 

A boat goes downstream in one-third the time it takes to go upstream. Then the ratio between the speed of boat in still water and speed of the stream is