Whoa...
While reading a book, I ran across what seemed like a really simple math problem that the author got wrong…got all pissed off because he was so sure that my solution was wrong.
So I did the scientific thing, and ran a test…and I’ll be damned…..
Remember the old game show, where there were three doors, and you choose a door and win a prize?
Imagine you are a contestant. Also, forget everything you know about game show psychology and hosts trying to scare you away from your prize. Consider the following as a math problem, plain and simple.
There are three doors. Behind one of the doors is an automobile. Behind the other two are goats.
Let’s say you choose door number one.
The host (who knows whats behind each door) opens door number two, and shows you a goat. He then asks you, would you like to switch?
Your answer:
A) Doesn’t matter. The odds now are 50-50…one doors is a car, the other is a goat. B) Yes, I’ll switch, because if I switch I am more likely to win!
If you picked A, like me, you are wrong.
Sorry. It’s B. Your odds of winning by sticking with the same door are only 33%. Your odds of winning if you switch are 66%.
Why? Honestly, I can’t explain it, which is why being told this without an explanation pissed me off. But, after conducting a little experiment with my wife in which we played the game over and over again about 30 times and watched the results come out, I can demonstrate it.
First, lets start over again, and show what’s behind each door:
1 - Goat 2 - Goat 3 - Automobile
Now, lets say you picked door one. The host shows you whats behind door two, and you switch to door 3. You win. Now, lets say you picked door two. The host shows you whats behind door one, and you switch to door 3. You win. Now, lets say you picked door three. The host shows ou whats behind door two, and you switch to door 1. You lose. If you switch, you win 2/3rds of the time.
Now, lets say you picked door one. The host shows you whats behind door two, and you stay with door one. You lose. Now, lets say you picked door two. The host shows you whats behind door one, and you stay with door two. You lose. Now, lets say you picked door three. The host shows ou whats behind door two, and you stay with door three. You win. If you stay, you win 1/3rd of the time.
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