Two towns A and B are connected by a regular bus service with a bus leaving in either direction every T minutes. A man cycling with a speed 20 km/hr in the direction A to B notices that a bus goes past him every 18 minutes in the direction of his motion, and every 6 minutes in the opposite direction. What is the period T of the bus service and with what speed do the buses ply on the road. Assume the buses ply with constant speed on the road.