A and B are any two events of a finite sample space U. The rule of obtaining the probability of the event AnB which corresponds to the occurrence of two events A and B simultaneously, is called the rule of multiplication of probability. This rule is written as under:
- P (A ∩ B) = P (A) . P (B | A)
OR
P (A ∩ B) = P (B) . P (A|B)
- For two independent events law of multiplication of probability is written as under:
- P(A ∩ B) = P(A) P(B)
- P (A’ ∩ B’) = P (A’) . P (B’)
- P(A ∩ B’) = P(A) – P(B’)
- P(A’ ∩ B) = P (A’) . P (B)
