If an anchored boat is rocked by waves whose crests are 80 m apart and whose velocity is 20 m/s, then the time required by the crests to reach the boat is ___.

In a stream running at 3 km/h, a motorboat goes 12 km upstream and back to the starting point in 60 min. Find the speed of the motor boat in still water. (in km/h)

A boat at anchor is rocked by waves whose consecutive crests are 125 m apart. The velocity of the wave of the moving crests is 25 m/s. What is the frequency of the rocking of the boat?

A boat covers a distance of 14 km upstream and 16 km downstream in 9 hours. It covers a distance of 12 km upstream and 40 km downstream in 11hours. What is the speed (in km/hr) of the boat in still water?

A man, rowing a boat, covers a distance of 16 km in two hours downstream. He covers half the distance in same amount of time when rowing upstream. Calculate the speed of the stream.

A boat cover row 12 km upstream in 4 hours and can cover the same distance downstream in 3 hours. What is the speed (in km/hr) of the boat in still water?

A boat goes 8 km upstream and 12 km downstream in 7hours. It goes 9 km upstream and 18 km downstream in 9 hours. What is the speed (in km/h) of the boat in still water?