What is multiplication rule in probability?
Given two events, A and B, the conditional probability rule
states that
P(A and B) = P(A given that B has occurred)*P(B)
If A and B are independent, then the occurrence (or not) of B
makes no difference to the probability of A happening. So that
P(A given that B has occurred) = P(A)
and therefore, you get
P(A and B) = P(A)*P(B)