Five Englishmen boarded a train just behind five Scots, who, as a group had only purchased one ticket. Just before the conductor came through, all the Scots piled into the toilet stall at the back of the car. As the conductor passed the stall, he knocked and called "Tickets, please!" and one of the Scots slid a ticket under the door. It was punched, pushed back under the door, and when it was safe all the Scots came out and took their seats. The Englishmen were tremendously impressed by the Scots' ingenuity.
On the trip back, the five Englishmen decided to try this themselves and purchased only one ticket. They noticed that, oddly, the Scots had not purchased any tickets this time....
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Anyway, again, just before the conductor came through, the Scots piled into one of the toilet stalls, the Englishmen into the other. Then one of the Scots leaned out, knocked on the Englishmen's stall and called "Ticket, Please!" When the ticket slid out under the door, he picked it up and quickly closed the door.