Boats and Streams - General Questions

A man can row downstream at 25 km/hr and upstream at 9 km/hr. What is the speed of the stream?

A boat goes 48 km/hr downstream and 12 km/hr upstream. What is the speed of the boat in still water?

A man takes 5 times as long to row a distance upstream as to row the same distance downstream. If the speed of the boat in still water is 6 km/hr, what is the speed of the stream?

A man can row downstream at 24 km/hr and upstream at 18 km/hr. What is the speed of the stream?

A boat goes 50 km/hr downstream and 6 km/hr upstream. What is the speed of the boat in still water?