From Noel Whittaker's latest newsletter

The contestant is faced with three doors. There is a new car behind one door and a goat behind each of the other two doors – the contestant has to choose the right door if they are to win the car. In the example given in the book, the contestant chooses a door, and before it is opened the compere opens one of the other two doors to reveal a goat. This means that the car is behind one of the remaining two doors.

The compere then asks the contestant if he would like to switch from his original choice.

This is the question – is he better off to stick with his original choice or switch? Most people will say he should stick with the original choice, but the correct answer is to switch. You see, the original choice had a two-thirds chance of being wrong, but now one door has been eliminated, the other door has a 50% chance of being right.

Most people I discussed this with do not agree with the answer and will go to great lengths to tell you why the correct answer is wrong. Apparently this is such a famous puzzle that there is a large section devoted to it on Wikipedia.

http://en.wikipedia.org/wiki/Monty_Hall_problem

The compere then asks the contestant if he would like to switch from his original choice.

This is the question – is he better off to stick with his original choice or switch? Most people will say he should stick with the original choice, but the correct answer is to switch. You see, the original choice had a two-thirds chance of being wrong, but now one door has been eliminated, the other door has a 50% chance of being right.

Most people I discussed this with do not agree with the answer and will go to great lengths to tell you why the correct answer is wrong. Apparently this is such a famous puzzle that there is a large section devoted to it on Wikipedia.

http://en.wikipedia.org/wiki/Monty_Hall_problem

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