In probability theory, the multiplication rule is used to determine the probability that two events, *A* and *B,* both occur. As with the addition rules, the notation for multiplication rules of probability are most commonly seen in terms of sets: P(*A*∩*B*) = P(*A*|*B*) • P(*B*) or P(*A*∩*B*) = P(*B*|*A*) • P(*A*), in which P(*A*) represents the probability that event *A* will occur, P(*B*) represents the probability that event *B* will occur, and P (*A*∩*B*) is translated as the probability that event *A* and event *B* will both occur. In addition, P(*A*|*B*) is the conditional probability that event *A* occurs given that event *B* has already occurred, and P(B *A)* is the conditional probability that event *B* occurs given that event *A* has already occurred. Similar to the addition rules, if there are independent events (or those that have no influence on one another), the equation reduces to P(*A*∩*B*) = P(*A*) • P(*B*).