A man covered a certain distance by a train at the speed of 40 km/hr and covers the same distance back by walking at the speed of 8 km/hr. Ifthe whole journey took 12 hours, then what is the one side distance (in km)?
A and B together can do a piece of work in 36 days, B and C together can do it in 24 days. A and C together can do it in 18 days. The three working together can finish the work in