How much toilet paper would you need to cover Texas? How many vacuum cleaners are made a year? Can you swim faster in water or in syrup? How would you weigh your head? If your answer to these was, "who cares?" your chances of ever working at Google, Microsoft, Wal-Mart, most of the Fortune 500, or, increasingly, the corner shoe store, are slim. Offbeat, brain-teasing questions are all the rage right now with interviewers. So says science writer William Poundstone, author of the new book, "Are you Smart Enough To Work At Google?" Its' daunting subtitle: "Trick Questions, Zen-like Riddles, Insanely Difficult Puzzles, and Other Devious Interviewing Techniques You Need to Know to Get a Job Anywhere in the New Economy."