The Monty Hall Paradox - Suppose you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1 [but the door is not opened], and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
You are actually twice as likely to win if you switch.
For there to be a 100% chance two people share the same birthday there must be 366 people.
A 99% chance is reached by 57 people and a 50% chance by just 23.
6% of men propose over the telephone.