Wait and watch

At the station, each lawyer bought a ticket whereas the engineers bought only one ticket between them.

"How are you going to travel on a single ticket?" asked a lawyer.

"Wait and watch" answered one of the engineers.

When they boarded the train, the lawyers took their seats, but the three engineers crammed into a toilet and closed the door behind them. Shortly after the train started, the ticket collector arrived. He knocked on the toilet door and asked, "Ticket please." The door opened just a crack and a single arm emerged with a ticket in hand. The ticket collector took it and moved on. Seeing this, the lawyers decided to the same thing on the return trip.

So when they got to the station, they bought only one ticket. To their astonishment, the engineers didn't buy any.

"How are you going to travel without a ticket?" asked one of the perplexed lawyers.

"Wait and watch" answered an engineer.

In the train, the three engineers crammed into a toilet and the three lawyers into another nearby. Soon after the train started, one of the engineers got out of the toilet and walked to one where the lawyers were hiding. He knocked on the door and said, "Ticket, please."