Carpooling
Although cities encourage carpooling to reduce traf?c congestion, most vehicles carry only one person. For example, 70% of vehicles on the roads in the Minneapolis-St. Paul metropolitan area are occupied by just the driver.
(a) If you choose 12 vehicles at random, what is the probability that more than half (that is, 7 or more) carry just one person?
(b) If you choose 80 vehicles at random, what is the probability that more than half (that is, 41 or more) carry just one person?