The multiplication rule is just a rearranged version of the Bayes rule. $ \begin{align} \mathbf P(A \vert B) &= \frac{\mathbf P(A \cap B)}{\mathbf P(B)} \\[8pt] \mathbf P(A \cap B) &= \mathbf P(A \vert B) * \mathbf P(B) \\[8pt] \mathbf P(A \cap B) &=\mathbf P(B \vert A) * \mathbf P(A) \end{align} $ This extend to the intersection of 3 or any $n$ events: $ \begin{align} \mathbf P(A \cap B \cap C)&= \mathbf P(A) * \mathbf P(B \vert A) * \mathbf P(C\vert A \cap \mathbf B) \\ \mathbf P(A_1 \cap \dots \cap A_n)&= \mathbf P(A_1)*\prod_{i=2}^n \mathbf P(A_i\vert A_{i-1} \cap \dots \cap A_1) \end{align} $ It can also be viewed as a stepwise decision process, with increasing conditions at each step. ![[probability-multiplication.png|center|400]]