Chandigarh and Ambala are connected with a regular bus service. A bus leaving in
either direction every T minutes. A boy cycling with a speed of 10 km ` h^(-1) ` from Chandigarh to Ambala notices that a bus crosses him after every 15 minutes towards Ambala and after every 5 minutes towards Chandigarh. Calculate the time T and the speed of the buses. Assume that speed of buses is constant.

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 of 20 km h^(-1) in the direction A to B notices that a bus goes past him every 18 min in the direction of his motion, and every 6 min in the opposite direction. What is the period T of the bus service and with what speed (assumed constant) do the buses ply on the road ?