numbered,2,..,128, and each ticket has the number of the seat the number of the audience is to sit in. The audience enters the theatre one at time. but first one to enter dose not notice the number of the seat on the ticket and sits in random eat. After that, each person sits in their assigned seat if it is unoccupied, and one of unoccupied seats at random otherwise. the probability that the last number of audience to enter gets to sit in their assigned seats is 50/50 (0.5) but why is it 50/50 chance? explain it ?