In one hour, a man rows his canoe against the stream at 11 km/h and along the stream at 23 km/h. What is the speed (in km/h) of the stream?

6

We know that,

Upstream speed = Speed of boat - speed of stream

Downstream speed = Speed of boat + speed of stream

Given,

Upstream speed = 11 km/h

Downstream speed = 23 km/h

Let the speed of the canoe = x km/hr

and current =  y km/hr

So, (x + y) = 23      ----(1)

(x – y) = 11      ----(2)

From equation (1) and equation (2)

x = 17 and y = 6.