According to USA Today (March 18, 1997), of 4 million workers in the general workforce, 5.8% tested positive for drugs. Of those testing positive, 22.5% were cocaine users and 54.4% marijuana users.
(a) What is the probability that of 10 workers testing positive, 2 are cocaine users, 5 are marijuana users, and 3 are users of other drugs?
(b) What is the probability that of 10 workers testing positive, all are marijuana users?
(c) What is the probability that of 10 workers testing positive, none is a cocaine user?