Speed of river is 6 km/hr. Speed of a motorboat in still water is 30km/hr. How much distance can it cover downstream in 24minutes?

14.4 Km

Speed of stream/river i.e. y = 6 km/hr

Speed of motorboat in still water i.e. x = 30 km/hr

Downstream speed i.e. x + y = 36 km/hr

As we know,  

Speed = \(\frac{ Distance}{ Time}\)

36 = \(\frac{\text{ Distance x 60}}{ 24}\)

36 = \(\frac{\text{ Distance x 5}}{ 2}\)

36 x 2 = 5 Distance

Distance = 14.4 km