Three Ohio State grads and three U. of Michigan grads are traveling by train
to a conference. At the station, the three U. of Michigan grads each buy
tickets and watch as the three Ohio State grads buy only a single ticket.
"How are three people going to travel on only one ticket?" asks a U. of
Michigan grad. "Watch and you'll see," answers the Ohio State grads.

They all board the train. The U. of Michigan grads take their respective
seats but all three Ohio State grads cram into a rest room and close the
door behind them. Shortly after the train has departed, the conductor comes
around collecting tickets. He knocks on the rest room door and says,
"Ticket, please." The door opens just a crack and a single arm emerges with
a ticket in hand. The conductor takes it and moves on. The U. of Michigan
grads saw this and agree it was quite a clever idea. So after the
conference, the U. of Michigan grads decide to copy the Ohio State grads on
the return trip and save some money.

When they get to the station, they buy a single ticket for the return trip.
To their astonishment, the Ohio State grads don't buy a ticket at all. "How
are you going to travel without a ticket?" asks one perplexed U. of Michigan
grad. "Watch and you'll see," answers an Ohio State grad. When they
board the train the three U. of Michigan grads cram into a rest room and the
three Ohio State grads cram into another one nearby. The train departs.
Shortly afterward, one of the Ohio State grads leaves his rest room and
walks over to the rest room where the U. of Michigan grads are hiding. He
knocks on the door and says, "Ticket, please..."