A boat takes 6 hours to cover 36 km downstream and 8 hours to cover 32 km upstream. Then the speed of the stream is?
4km/hr
3km/hr
2km/hr
1km/hr
Explanation:
Speed downstream = $\dfrac{Distance}{Time}$=$\dfrac{36}{6}$=6km/hr
Speed upstream = $\dfrac{Distance}{Time}$=$\dfrac{32}{8}$=4km/hr
Speed of stream =$\dfrac{1}{2}\left(Downstream\:Speed-Upstream\:Speed\right)$
Required speed =$\dfrac{1}{2}\left(6-4\right)km/hr$
=$\dfrac{1}{2}\times 2$
=1km/hr