Question

A Boat takes 3 hours to go 45 km upstream and IT return back in 9 hours find the speed of the stream and that of the boat in still water

Answer 1

15 km. / hr. is the speed of boat and 5km. / hr. is the speed of the water

Answer 2

Answer:

speed of boat is 10 km/hr and speed of current is 5 km/hr.

Step-by-step explanation:

let speed of boat is u km/hr and speed of current is v km/hr.

as we know

distance = speed * time

acc. to question it takes 3 hours to go 45 km upstream

45 = (u+v)* 3

⇒u+v = 15 - - - - - 1

and IT return back in 9 hours

45 = (u-v)* 9

⇒u-v = 5 -- - - - -2

by solving eq 1 and 2

u = 10

v= 5

so speed of boat is 10 km/hr and speed of current is 5 km/hr.