MindGames: Probability Games

Think outside the box!

Card Shark, Marble Madness, Sock It to Me! & Dizzy Walk

In the beginning there's "Jewels of Xanadu" on the cover—where the chances of unlocking the special color-coded safe could be 1 in millions or 1 in 64, depending on where you start. And once you've survived that, another 25 mind-stretching puzzles await.

• Win a coin-toss game with three friends, calculate the real odds of winning the lottery, predict the chance of pulling the one green marble out of a box of red ones. Think like a mathematician, making sense of seemingly random events.
• Bring a pencil, but remember—(1) you don't have to be a whiz to play, because (2) the most important skills you'll need are curiosity and an open mind. (Solutions and explanations are provided of course!)