Boats and Streams Important Formulas - Aptitude Questions and Answers

Still water: The speed of water in the river is zero

Stream water: The water in the river is flowing or moving.

Speed of Boat and Stream:

Assume the man’s rate of rowing in still water = x km/hr

Speed of stream = y km/hr

(a) Down stream rate = (x + y) km/hr

(i.e.) Direction of rowing and direction of flow is same.

(b) Up stream rate = (x – y) km/hr

(i.e.) direction of rowing and direction of stream are opposite.

Speed of still water and stream

Assume, speed downstream = a km/hr

Speed upstream = b km/hr

Then, speed in still water =

(a + b) km/hr

Rate of stream =

(a - b) km/hr