Solve Lewis Carroll's Tricky 'Pillow Problem' with Gizmodo's Monday Puzzle.

Lewis Carroll, the author of Alice's Adventures in Wonderland, was also a mathematician who created a book of mathematical puzzles called "Pillow Problems." One of his famous puzzles is the "Pillow Problem" which asks what are the chances that the other marble in an opaque bag containing one marble that has a 50/50 chance of being black or white, but you don’t know which color it is, is also white if you take a white marble from your pocket and add it to the bag, shake up the two marbles in the bag, reach in, and pull a random one out, which happens to be white. The solution will be posted next Monday along with a new puzzle.