A girl says this to her best friend: “I was born in 1955, and I celebrated my 17th birthday last weekend.†Her best friend thinks she’s lying, but she’s actually correct. How is that possible?
How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?
Four cars come to a four-way stop, each coming from a different direction. They can’t decide who got there first, so they all go forward at the same time. All 4 cars go, but none crash into each other. How is this possible?