Why does the number 3 repeats itself in the Islam?

I've realized that during the Wudu, hands, arms, face, etc are all washed 3 times each one. Also I've noticed that during the Salat, many prayers are repeated 3 times. Also, to divorce, **talaq** word has to be repeated 3 times. Is there any reason to explain why does the number 3 repeats itself in the Islam? Or is it just a coincidence? *Note: I'm not Muslim, just an agnostic trying to understand this amazing religion better.*