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 man starts walking from a place X and reaches the place Y in 12 hours. He travels 3/7th of the total distance at the speed of 3 km/hr and the remaining distance at the speed of 4 km/hr. What is the distance (in km) between X and Y?