Question

A log boat travels6 km in 1hour

Answer 1

Let the velocity of the boat be v km/hr and velocity of the current be u km/hr

When the boat goes in still water =v=6 km/hr

When the boat goes against the current, its velocity is =v−u=(6−u) km/hr

For distance S, time taken in still water to cover the distance =

6

S

hours

For same distance S, time taken while going against the current =

6−u

S

hours

According to given condition,

6−u

S

=3×(

6

S

)

⇒

6−u

1

=

2

1

⇒6−u=2

⇒u=4 km/hr