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).