Please help with question 5

5. From a survey it has been determined that 45% of undergraduate college students have a job. (You may assume one student's job status is independent of that of another student.) SYMBOLIZE EACH STATEMENT FIRST. - danger a. If four students are chosen at random, what is the probability that all four of them have a job? b. What is the probability that at least one of the four students does not have a job? P( all Job)