You have 12 black socks and 12 white socks mixed up in a drawer. You’re up very early and it’s too dark to tell them apart. What’s the smallest number of socks you need to take out (blindly) to be sure of having a matching pair?
Three socks. If the first sock is black, the second one could be black, in which case you have a matching pair. If the second sock is white, the third sock will be either black and match the first sock, or white and match the second sock.
You’re standing 11 feet away from a doorway and with each step you move halfway to the doorway. How many steps will it take for you to get to the doorway?
Technically, the answer is infinity. If you keep going halfway, you’ll never actually make it to the doorway.
But in practice, after 10 steps you’ll be 1/8th of an inch to the doorway and anyone behind you would say to stop being a baby and take a real step through the doorway already.
