> Cheers Thanks, anyway i already did writing and other stuff but the only > problem is that i don't know to start my code. :( Try to create a Vehicle class where you compute the arrival time and the number of passengers based on a departure time. Then make a loop of say 500 vehicles (to be sure everybody arrive at the end) and create a list of vehicles that are launched every 5-35s. Do not forget to sort the list based on arrival time rather than departure time. In the end, it should give you something like [...] 442 passengers where there after 654 seconds 444 passengers where there after 691 seconds 448 passengers where there after 717 seconds 449 passengers where there after 746 seconds 489 passengers where there after 761 seconds 529 passengers where there after 790 seconds Cheers, -- JJ Fleck PCSI1 LycñÆ KlñÃer