Final answer:
The multiplication rule in set theory states that the probability of two events occurring together is equal to the product of their individual probabilities, given that one event has already occurred.
Step-by-step explanation:
The multiplication rule in set theory states that if A and B are two events defined on a sample space, then the probability of both events occurring is equal to the product of their individual probabilities, given that event B has already occurred. Symbolically, this can be represented as P(A AND B) = P(A | B) * P(B). If A and B are independent events, then the probability of their intersection is equal to the product of their individual probabilities, which can be written as P(A AND B) = P(A) * P(B).