There are two Guards in a room. there are two doors in the room. one door leads to life, the other, death. one guard only tells the truth, the other only lies. you can ask one question to get out of the room, what is it ?
Ask either of the Guards wich door leads to life and you will get the same answer - "sorry mate, I only took over at Crewe - tickets please - and anyway they call us Customer Special Service Passenger Interface Technicians now (or CESSPIT for short, cos we are full of sh*t)"