有人想动脑筋吗？这有道统计题

A game show host has one car behind one of the three doors. The other two doors open to a goat. Now, the game show host asks the contestant, to pick one door. He chooses door number one. Then, the host opens the door number three. There is a goat!! Now, the host asks whether the contestant wants to change his choice.

If you were the contestant, would you accept the offer?