Three Engineers and three Managers are going to a conference and had to travel by train to get there. At the station， the three Managers bought their three tickets and watched as the three Engineers bought only a single ticket. “How are three people going to travel on only one ticket？” asked a Manager. “Just watch and you'll see，” answered an Engineer.
They all board the train and the Managers took their seats and watched as all three Engineers cram into a restroom and close the door behind them. The train departed and shortly afterward， the conductor came around collecting tickets. He knocked on the restroom door and said， “Ticket， please.” The door opened just a crack and a single arm emerged with a ticket in hand. The conductor took it and moved on.
The Managers saw all this and agreed it is quite a clever idea. So after the conference， the Managers decide to copy the Engineers on the return trip and save some money （expense reports）。 When they got to the station， they bought a single ticket for the return trip. But to their astonishment， the Engineers didn't buy a ticket at all.
“How are you going to travel without a single ticket？” asked one Manager.
“Just watch and you'll see，” answered an Engineer.
They board the train. The three Managers cram into a restroom compartment and the three Engineers cram into an another one nearby. The train departed. Shortly afterward， one of the Engineers left his restroom， walked over to the Managers stall， knocked on the door and said， “Ticket， please.”