Quantitative Aptitude - Boats and Streams - Formula & Concept Tutorial

1. Downstream -

In water , the direction along the stream is called downstream.

2. Upstream –

In water , the direction against the stream is called upstream.

3. If the speed of boat in still water is u km/hr and the speed of the stream is v km/hr , then

a = Speed downstream = ( u + v ) km/hr = u + v

b = Speed upstream = ( u – v ) km/hr = u – v

4. If the speed downstream is  a km/hr and speed upstream is b km/hr then

u = Speed in still water =

v = Rate of stream =

5. Suppose a boat cover a certain distance at x km/hr and an equal distance at y km/hr the boat reverse.

Then the average speed during the whole journey is