Dealing with Conditional Probability today.
Conditional probability is the probability of an event occuring given that another event has already occurred. For instance, the probability that a person gets lung cancer if we know he’s a heavy smoker. The probability of rolling a twelve on two dice if the first one rolled six.
Conditional probability is essentially the probability of the entire event divided by the probability of the assumed event. The probability of the entire event is the intersection of the probabilities of each stage.
See chapter 7.4