The Book of IQ Tests

Think you’re smart? Prove it! Twenty-five brain-stumping IQ quizzes, featuring wordplay, diagrams, numerical challenges, and more, provide an intriguing challenge. Here’s just one sample of what’s in store: Solve the clues to find four six-letter words. The same three letters are represented by XYZ in each word.

X Y Z _ _ _ clue : fleet
_ X Y Z _ _ clue : heat
_ _ X Y Z _ clue : beguiles
_ _ _ X Y Z clue : remove defensive capability

Answer:
2. Armada, warmth, charms, disarm. XYZ = ARM