1, 2, 3

O concorrente escolhe a porta 1 para tentar ganhar um automóvel.
O apresentador, Carlos Cruz, manda abrir a porta 2 mostrando uma bota e diz:
- Agora, dou-lhe a oportunidade de mudar a escolha para a porta 3.
Deve o concorrente manter a escolha ou mudar para a porta 3?

PS: É óbvio que não adianta mudar a escolha. Mas o óbvio está errado.

Decision/Monty hall

You are a participant on "Let's Make a Deal." Monty Hall shows you three closed doors. He tells you that two of the closed doors have a goat behind them and that one of the doors has a new car behind it. You pick one door, but before you open it, Monty opens one of the two remaining doors and shows that it hides a goat. He then offers you a chance to switch doors with the remaining closed door. Is it to your advantage to do so?