Aptitude Boats and Streams Concepts and Formulas
General terms:
1) Still water: The water of a river or any other water body which is not flowing is known as still water.
2) Stream: It is the flowing water of a river which is moving at a certain speed.
3) Upstream: The boat or a swimmer moving against the stream is known as moving upstream i.e. against the flow of water.
4) Downstream: The boat or a swimmer moving along the stream is known as moving downstream i.e. along the flow of water.
Points to remember:
1) If the speed of the boat or swimmer is X km/hr and the speed of the stream is Y km/hr,
The speed of the boat or swimmer in the direction of the stream is known as speed downstream. It is given by;
Speed downstream= (X+Y) km/hr
And, the speed of the boat or swimmer against the stream is known as speed upstream. It is given by;
Speed upstream= (X-Y) km/hr
2) Speed of man or boat in still water is given by;
= 
( speed downstream + speed upstream)
3) Speed of the stream is given by;
= 
( speed downstream – speed upstream)
4) A man can row at a speed of X km/hr in still water. If the speed of the stream is Y km/hr and the man rows the same distance up and down the stream, his average speed for the entire journey is given by;
= 
= 
km/hr
5) A man can row a boat in still water at X km/hr. If the stream is flowing at Y km/hr it takes him t hours more to row upstream than to row downstream to cover the same distance. The distance is given by;
Distance = 
6) A man can swim in still water at X km/hr. If the stream is flowing at Y km/hr it takes him t hours to reach a place and return back to the starting point. The distance between the place and the starting point is given by;
Distance = 
7) A boat or swimmer covers a certain distance downstream in t1 hours and returns the same distance upstream in t2 hours. If the speed of the stream is Y km/hr, the speed of boat or man in still water is given by;
= Y 
km/hr
8) A boat or swimmer takes K times as long to move upstream as to move downstream to cover a certain distance. If the speed of the stream is Y km/hr, the speed of the boat or man in still water is given by;
= Y 
km/hr
Aptitude Boats and Streams Test Paper 1
Aptitude Boats and Streams Test Paper 2
Aptitude Boats and Streams Test Paper 3
Aptitude Boats and Streams Test Paper 4