Calculate P(A|B) using the definition P(A∩B)/P(B) with step-by-step explanation.
Conditional probability P(A|B) is the probability of event A occurring given that event B has already occurred. It is defined as the ratio of the joint probability P(A∩B) to the marginal probability P(B).
P(A|B) = P(A ∩ B) / P(B)
When A and B are independent events — knowing B occurred does not change the probability of A.
No. P(A|B) = P(A∩B)/P(B) while P(B|A) = P(A∩B)/P(A). They are related by Bayes' theorem.