Trail Users According to Trail Count, the annual survey of San Jose's off-street bicycle and pedestrian trail users, approximately 24% use trails daily. Suppose 12% use trails daily and exercise, and 8% use trails daily for commuting. Suppose a trail user is randomly selected.
a. Given that the person uses trails daily, what is the probability that he uses the trails for exercise?
b. Given that the person uses trails daily, what is the probability that she uses the trails for commuting?
c. If the person uses trails daily, what is the probability that he does not use the trial for commuting?