I have come to the same conclusion as some others. When workign the problem you have a 1/3 chance of picking the car if you should choose first. If your friend is allowed to choose first it leaves you with a 1/2 chance considering he were to pick a goat first. The fact that there are two goats means that this mulitplication must be performed twice, thus there is a 1/3 chance again

Alumni Liaison

Ph.D. on Applied Mathematics in Aug 2007. Involved on applications of image super-resolution to electron microscopy

Francisco Blanco-Silva