1. McDonald's has decided to keep their doors open all night. There are 15 employees that have volunteered for the night shift.
a) If a night crew consists of 4 employees, how many different crews are possible? he employees are ranked 1,2,..,15 in order of competence, how many of b) If t these crews would not have the best employee? c) How many of the crews would have at least 1 of the 5 best employees? d) If one of these crews is selected at random to work on a particular night, what is the probability that the best employee will not work that night?
