P ⁡ ( C | G ) = P ⁡ ( G | C ) ⁢ P ⁡ ( C ) P ⁡ ( G ) Q327069 car is behind door 1 Monty opens door 2 to show the goat Q327069 Monty opens door 2 to show the goat car is behind door 1 Q9492 car is behind door 1 Q9492 Monty opens door 2 to show the goat P(C|G)=\frac{P(G|C)P(C)}{P(G)}