I am very surprised at a result which I checked via google.

Say you at a casino found out something one out of 500 chance happening happened. You went to a second independent casino and 1/500 happened too. What is the probability this happened? 1out of 250000? According to google it is multiplicative.

So I went to 8 casinos and this by itself unlikely event happened. What is the odds? Or we mistook something?