A) Of the patients at a cardiac rehabilitation centre, 46% lead a sedentary lifestyle and have had a heart attack. If 80% of the patients lead a sedentary lifestyle, find the probability that a randomly selected patient has had a heart attack, given that he or she leads a sedentary lifestyle.

B) In a ten day period, the probability of a certain number of outbreaks of a contagious viral infection is represented in the table below.

What is the probability of having 1 or more outbreaks?

x P(x)

0 0.30

1 0.40

2 0.27

3 0.02

4 0.01