Three lawyers and three engineers are traveling by train to a conference. At the station, the three lawyers each buy a ticket and watch as the three engineers buy only a single ticket.
"How are three people going to travel on only one ticket?" one of the lawyers asks.
"Watch and you'll see," one of the engineers replies.
All six men board the train. The three lawyers sit together, but the three engineers cram themselves into a restroom and close the door behind them. A short time later, the conductor comes around to collect tickets.
"Ticket, please," he says as he knocks on the restroom door. The door opens just a crack and an arm emerges with ticket in hand. The conductor takes it and moves on. The lawyers, who observed the scene, all agree it was a clever idea.
On their way home after the conference, the lawyers decide to copy the engineers to save money. When they get to the train station, they buy a single ticket for the return trip. To their astonishment, the engineers don't buy a ticket at all.
"How are you going to travel without a ticket?" one of the lawyers asks.
"Watch and you'll see," one of the engineers says.
When they board the train, the three lawyers cram themselves into a restroom, while the three engineers cram into another restroom nearby. Shortly after the train departs, one of the engineers leaves the restroom and walks over to the restroom where the lawyers are hiding. He knocks on the door and says, "Ticket, please."