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Best explanation to understand and solve the boat and stream problems.

In this section, you can take up the aptitude test based on BOAT AND STREAM.

This is one of the interesting concepts in arithmetic aptitude. It’s basic concept is about speed, time and distance.

In most of the entrance exams, competitive exams, and interviews you will have many questions based on this topic.

These questions are very easy to answer and can boost up your score easily. The only thing is that you have to understand the concept of the question before answering it. 

To make it easier for you, we have given the explanations about the important terms of this topic and also some important formulas to work out the problems.

Learn about the topic clearly and apply the given formulas in your exams. You can also take up the test provided in our website and practice for your exams. 

Concept Of Boat And Stream

The concept of boat and stream is very easy to understand because the topic is based on speed, time and distance. There are some important terms in this section so that it will help you to understand the concept more clearly.

General Terms:

1. Still Water – Still water means the water of river or any water body which is not moving and staying still.

2. Stream – Stream refers to the flow of water in the river or in any water body at a certain speed.

3. Upstream – Upstream refers to the boat or a swimmer moving in the opposite direction of the flow of water or with the stream.

4. Downstream – Downstream refers to the boat or swimmer moving along with the direction of flow of water or with the stream.  

Formulas And Points To Remember

Let us consider that the speed of boat or swimmer is ‘x’ km/hr and the speed of stream s ‘y’ km/hr.

1. when the boat goes in downstream, the water will take the boat along with it. So the speed is calculated as 

Downstream = (x+y)km/hr

2. when the boat goes in upstream, the water will resist the boat to move forward because it is moving against the flow of water. So the speed is calculated as

Upstream = (x-y)km/hr

3. Speed of the boat in still water is calculated as: (upstream + downstream)

4. Speed of stream is given by: (upstream – downstream)

5. A boat goes in the speed of ‘x’ km/hr in still water and if the speed of stream is ‘y’ km/hr  the boat rows the same distance up and down the stream. So the average speed of the journey is calculated by

 Upstream downstream / Speed of the boat in still water =  ( (x+y) (x-y) / X )  km/hr

6. A man rows 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 = (x2-  y2) t / 2y

7. 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 = ( x2-  y2) t /  2x

8.  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 of  t2 + t1 / t2 –  t2 km/hr

9.  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 of K + 1 / K – 1 km/hr