Lets say you are supposed to give answer to following question:
"There are 252,200 words in Oxford English dictionary. What is the probability that for any randomly selected word a .com domain is still available for purchase"
Of course in real life the answer is close to Zero. There are many other places where I can tell you this will apply.
Another more relevant discussion is over here http://aioreference.com/denmark-kangaroo-orange-trick-mathematical-vs-real-life-probability/
Can you tell few of them?