The speed of a boat in still water is 5km/hr. If the speed of the boat against the stream is 3 km/hr, what is the speed of the stream?

2 Km/hr

Let,

Speed of boat in still water i.e. x = 5km/hr ----(1)

Speed of stream/current = y

According to the question:

Upstream speed (Us) = 3 km/h i.e. x - y = 3 km/h----(2)

Putting (1) in (2)

x - y = 3

5 - y = 3

y = 2 km/hr