It may take a sharp mind to work for Google, as author William Poundstone claims that the search giant requires its applicants to answer perplexing trivia questions and riddles.

William Poundstone claims to have unlocked the secret of acing an interview at Google and other top technology firms, and is revealing his secrets in a new book.

In Are You Smart Enough to Work at Google, William Poundstone describes several interview questions that he claims that his tips will increase an applicant’s chances of not only getting hired by Google, but anywhere.

He told ABC News: “HR departments are running scared, asking themselves, <<How can we make sure our questions have predictive power for how well someone will do on the job?>>”

William Poundstone claims that Google requires its applicants to answer perplexing trivia questions and riddles

William Poundstone outlines several of the brain teasers that are said to be used by actual Google interviewers, from “How much toilet paper would you need to cover Texas” to “Can you swim faster in water or syrup?”

He told ABC News that whether a job applicant can answer the question or not, it’s best to ask follow up questions to show that you recognize what is being asked.

Google would not comment on William Poundstone’s book, but some are quick to point out that the interview questions that have been circulating the web for several years are works of fiction.

Gayle Laakmann McDowell, the founder of CareerCup.com who has worked at Google, Microsoft and Apple, wrote in a 2010 blog post that “brain teaser”-esque questions are simply not used by Google.

He wrote: “Whatever the original source is, these questions are fake. Fake fake fake.”

GOOGLE’S BRAIN BUSTERS

Why are manhole covers round?

How many piano tuners are there in the entire world?

How much toilet paper would you need to cover Texas?

You are shrunk to the height of a nickel and thrown in a blender. The blades start moving in 60 seconds. What do you do?

How much should you charge to wash all the windows in Seattle?

How many vacuum cleaners are made a year?

Using only a four-minute hourglass and a seven-minute hourglass, measure exactly nine minutes – without the process taking longer than nine minutes.

Design an evacuation plan for San Francisco.

How would you devise an evacuation plan for San Francisco?

What number comes next in this pattern? 10, 9, 60, 90, 70, 66

Can you swim faster in water or in syrup?

A man pushed his car to a hotel and lost his fortune. What happened?

How many times a day do a clock’s hands overlap?