They're challenging, baffling, and wildly entertaining: here are 240 colorful, mind-boggling puzzles of every kind to sharpen anyone's thinking skills! Vivid optical illusions fool and tease the eye: try to find both a young girl and her grandmother in what seems to be a picture of only one woman. Or test those smarts on a different type of visual problem by figuring out which of six pieces isn't needed to make a cube. Sneaky lateral thinking puzzles are so tricky that there are extra clues to help: look at them first and then solve the riddle of why a tourist in London wouldn't ride the escalator in the subway station--even though he wanted to. It takes really creative reasoning to solve clever logic conundrums, including mathematical enigmas from the "addled arithmetician" and mini-mysteries to delight the armchair detective. And lots more stimulating fun!