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.
The letter H. It completes the list of letters that are vertically symmetrical. In other words, you can fold the top half of the letter over the bottom half and everything lines up.
The magic word – please. It makes people do things they otherwise wouldn’t be inclined to do. When parents are teaching children about manners, they call it the magic word and wait to fulfill a request until the child says please. Once the child says it, the parent feels bound to do it to show the child that it works.
This problem can be solved by preschool children in five to ten minutes, by programmers in an hour and by people with higher education…well, check it yourself.
