Question

The distance travelled by a boat downstream is 1½  times the distance travelled by it upstream in the same time. If the speed of the stream is

3 kmph, find the speed of the boat in still water.​

Answer 1

Answer:

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

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

Let the speed of a boat in still water be u km/hr and the speed of the stream be v km/hr, then:

Speed downstream = (u + v) km/hr

Speed upstream = (u - v) km/hr.

Let the speed downstream be a km/hr and the speed upstream be b km/hr, then:

Speed in still water =1/2(a+b) km/hr

Rate of stream = 1/2(a−b) km/hr