Billy recently won a contest to be on a hit trivia show, called "Trivillions", where the object of the game is to answer as many trivia questions as you can, and the more you answer, the more money you get.
Billy was psyched. He went to the store to buy a book on scarce facts. He found only two books. One was made in 2006 and the other was made in 1998. Since the old one was cheaper he went with that book.
He aced every question. The final question was, "How many oceans are there?" Easy one, he thought. When he gave his answer, "Four oceans", he got the question wrong! Why would he have not gotten the question wrong if he went with a current trivia book?
Because in 2000, another ocean was added around Antarctica, called the Southern Ocean. In 1998 there were only four oceans: the Arctic, Pacific, Atlantic, and Indian.
Today's brain teaser courtesy of Braingle.com.