Question

Suppose that a set of three traffic lights along one section of road operate independently (i.e., no communication or special timing between the lights). Since this is a fairly main road, the lights are green with a probability of 0.7 and red with probability 0.3. As you go through this stretch of road, What's the probability that :

At least one of the lights is red?

Males and females are observed to react differently to a given set of circumstances. It has been observed that 70% of the females react positively to these circumstances, whereas only 40% of males react positively. A group of 20 people, 15 female and 5 male, was subjected to these circumstances, and the subjects were asked to describe their reactions on a written questionaire. A response picked at random from the 20 was negative. what is the probability that it was that of a male?(using bayes' rule)

Answer 1