I can sleep at night again, now that I have resolved one of life’s most perplexing mysteries. All is well with the universe once more.

What is the persistent question that for so long stole my peace of mind? It is the riddle of Monty Hall and the goat behind Door Number Three.

The so-called Monty Hall problem is a counter-intuitive statistics puzzle that goes as follows: You have to choose one of three doors.  Behind one you will find a car; behind each of the others, you will find a goat. You pick Door #1, hoping for the car, of course. Monty Hall, the game show host, narrows your choices by opening Door #3 to reveal a goat. Then Monty offers you a choice:  you can stick with your original door or switch to Door #2.

What should you do? Simple logic suggests that there is no advantage to switching doors. With the elimination of Door #3, your odds improve from one-in-three to even-money.  It shouldn’t matter whether or not you switch: either way, you will still have a 50-50 chance.

But here human logic fails. By switching doors, you increase your odds from even money to two-thirds.

HERE’S WHY IT WORKS, AND WHAT IT MEANS TO US:
http://www.learning-mind.com/the-monty-hall-problem/