BRAIN TRIVIA
Logic puzzle: It’s pitch dark, and your sock drawer has 10 black socks and 10 white socks all mixed up. How many socks do you need to grab to be sure you have a matching pair?
(Hint: You don’t need a pair of a certain color. Any matching pair works!)
Hint:
There are only 2 colors. Think about the unluckiest way your grabbing could go.
Solution:
Just 3 socks!
Your first sock is black or white.
Your second sock might be the other color. That’s the unlucky case: one black, one white, no match yet.
Your third sock has to match one of them, because there are only 2 colors!
Lots of people guess 12, but that’s the answer to a different question. You would need 12 socks to be sure of getting a black pair (all 10 white socks could come out first, and then you would still need 2 black ones). For any matching pair, 3 is enough!