1) An elevator starts at the basement with 8 people (not including the elevator operator) and discharges them all by the time it reaches the top floor, number 6. In how many ways could the operator have perceived the people leaving the elevator if all people look alike to him? what if 8 people consisted of 5 men and 3 women and the operator could tell a man from a woman?
2) A total of 4 buses carrying 148 students from the same school arrives at football stadium. The buses carry respectively 40,33,25,50 students. One of the students is randomly selected. let X denote the number of students that were on the bus carrying this randomly selected students. one of the 4 bus drivers is also randomly selected. let Y denote the number of students on her bus. which of E[X] or E[Y] do you think is larger, why? also, compute E[X] and E[Y]
At basement: 8C0 = 1ways
At first floor: 8C1 = 8ways
At second floor: 8C2 = 28 ways
At 3rd floor: ...
This solution is comprised of a step by step explanation of probability concepts.