While i was there i read a book on (non-)theories and generalizations of a thing called joke* and came up with this one:
How many flight attendants do you need to change a light bulb?
- The first needs to check that the light bulb is really broken;
- the second flight attendant will inform the purser;
- and the last one informs the passenger that, sorry, unfortunately this technical item cannot be repaired but your complaint has been duly noticed.