Three engineers and three lawyers were going to a convention. At the train station to the convention, one engineer said, “We can get on the train with only one ticket.”
The other group laughed, but did not interject when the first group bought the ticket. When the conductor went around on the train for the tickets, the engineers all walked into the restroom. The conductor walked over, knocked on the door, and a single arm shot out holding the ticket, which the engineer took.
The engineers walked back to their seat after with no further problems. The other group applauded their idea.
On the way back from the convention, the lawyers announced how they were going to try the same trick as the first.
“In that case,” one engineer started, “We will travel with no ticket at all!”
The lawyers laughed at the engineers, but did not refuse their idea. On the train back, the conductor walked around to collect tickets, and the lawyers giggled to themselves as they got up and entered the restroom. Waiting a moment, the engineers all got up, walked to the lawyers’ restroom, knocked on the door, and an arm shot out with the ticket. The engineers took it, and entered the next restroom over.