A boat can travel 20 km downstream in 24 min. The ratio of the speed of the boat in still water to the speed of the stream is 4 : 1. How much time will the boat take to cover 15 km upstream? 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?