Smokers and Nonsmokers The participants at a
mathematics conference are housed dormitory-style, five to a
room. Because of an oversight, conference organizers forget
to ask whether the participants are smokers. In fact, it turns
out that 30$\%$ are smokers. Find the probability that Fred, a
nonsmoking conference participant, will be housed with:
(a) Exactly one smoker.
(b) One or more smokers.