Three accountants and three engineers on the train

Three accountants and three engineers all have to take a train to go to a special conference. At the ticket counter the accountants each buy a ticket but the engineers only buy one between the three of them. The accountants ask how are are they going to all travel with just one ticket. The engineers say "Watch this". when the train starts moving the three engineers all go into the bathroom together. when the conductor walks by he knocks on the door and asks "ticket please". one hand extends out of the bathroom with the ticket. The conductor moves along. The accountants agree that this is a very clever plan and decide to try it them selves on the return trip. However for the return trip when the accountants only buy one ticket the engineers by none. "how are all of you going to travel without any ticket?" the accountants ask. "Just watch" so the engineers. They all get onto the train the accounts all cram into one bathroom and the engineers cram into another. then one of the engineers leaves the bathroom and walks to the bathroom where the accountants are hiding, knocks on the door and says, "ticket please."