Multiplication Rule:
If a process can be broken into stages, and Stage 1 can be done in m ways,
and Stage 2 can be done in n ways, then the whole process can be done in
m × n ways.
More generally, if there are several stages (Stage 1, Stage 2, …, Stage k) with
n1, n2, …, nk options respectively, then the total number
of outcomes is
n1 × n2 × … × nk.
👉 We use this rule whenever we need to count how many combinations of choices are possible
across multiple independent steps (e.g., picking an outfit, building a password, planning a route).