A sailor goes 8 km downstream in 40 minutes and returns in 1 hour. Find the speed of the sailor in still water and the speed of the current.
Let the speed of the sailor in still water be v kmph and the speed of the current be u kmph.
According to question -
Speed of the sailor in upstream direction = v - u
Speed of the sailor in downstream direction = v + u
∴ 8/(v + u) = 2/3
⇒ v + u = 12.....(1)
and,
⇒ 8/(v - u) = 1
⇒ v - u = 8.....(2)
Adding equations (1) and (2), we get -
v = 10
Substituting the value of v in (2), we get -
u = 2
Thus, speed of sailor in still water = 10 kmph and speed of current = 2 kmph.