A boat running downstream covers 16 km in 2 hours. Covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water? * code example

Example: A boat covers a certain distance downstream in 1 hour, while it comes back in 1 hour 40 min. If the speed of the stream be 5 kmph, what is the speed of the boat in still water?

A boat covers a certain distance downstream in 1 hour, while it comes back in 1 hour 40 min. If the speed of the stream be 5 kmph, what is the speed of the boat in still water?