Paddling with the current, a canoeist can travel 30 km in 5 hours. Against the current, the canoeist takes 6 hours and 15 minutes to travel the same distance. Find the rate of the canoeist in still water and the rate of the current.
30 / 5 ==6 km/h - speed of the paddler with the current
30 / 6.25 ==4.8 km/h - speed of the paddler against the current.
[6 + 4.8] / 2 ==5.4 km/h - speed of the paddler in still water.
[6 - 4.8] / 2==0.6 km/h - the speed of the current.