Tell me about yourself. Why does this job interest you? How many quarters would you have to stack to reach the top of the Empire State Building?

Those were the questions Liz Kostak was asked during a phone screen with a major investment bank. Caught off guard, Liz didn’t make the cut. But today, her interview preparation includes not only examining a company’s annual report and checking for the latest news, but sitting down with a book of brainteasers to sharpen her puzzle-solving skills.

Ever since Microsoft made headlines in the mid-1990s for using brainteasers to identify the best and brightest, other companies have adopted this practice.

Designed to measure candidates’ intelligence, creativity and analytical skills, brainteasers and logic questions often involve obscure subjects. For example:


  • How many piano tuners are there in the world?
  • How many golf balls can you stuff into a Boeing 777?
  • What’s the size of the market for disposable diapers in China? For these types of the questions, the trick is to start big and take it one step at a time. For example, to determine China’s market-size for disposable diapers, you might:1. Estimate the population of China.
    2. Pick a percentage of that number to represent Chinese people of childbearing age.
    3. Divide that number in half to get the number of Chinese women.
    4. Estimate what percentage of those women has children.
    5. Then, knowing that Chinese families tend to have just one child, assume what percentage of those children are younger than three years old. 

    Use round numbers you can calculate on the spot. Your answer may not be exact, but the idea is to show your problem-solving skills as well as your ability to think on your feet. And don’t get hung up on not knowing the population of China or how many cubic inches are in a Boeing 777.

    “We know you can easily look those numbers up later,” says a recruiter for a major consulting firm who asked not to be named. “We’re not that concerned with whether a candidate comes up with the precise answer. We’re looking for insight into their thought process and whether they work thorough problems in a logical manner.”

    In fact there may be no single correct answer for some questions. Questions like: “How many ways can you think of to find a needle in a haystack?” “How would you design a bathroom for the CEO of the company?” and “If you could remove any one of the 50 U.S. states, which would it be?” serve as platforms for candidates to demonstrate their creativity and mental agility.

    Companies use the approach to cut through the pat, rehearsed answers many candidates give. “We want to know what you’re like. Not what you think we want you to be like,” says a partner at a major international consulting firm.

    “The only sure-fire way to fail at these questions is to be stumped,” she adds, advising candidates to “offer up your ideas even if they seem bizarre.”

    Successful candidates also recommend talking your interviewer through your thought process as you tackle the questions, to display your analytical ability. This also keeps you and the interviewer engaged in dialogue, which may give you some cues that could help you down the right track.

    The best advice according to Kostak, however, is to be prepared. Even though these types of questions are meant to make you “think on your feet,” there are resources you can use to make sure you put your best foot forward.

    William Poundstone’s book “How Would You Move Mount Fuji?” helps candidates think strategically about the brainteasers they may be asked and contains common questions companies are asking. And there are numerous websites and chat rooms circulating favorite puzzlers of specific companies and industries.

    After reading Poundstone’s book and honing her skills at, Kostak has received – and declined – four offers. Leaving us all with the puzzle: How many offers will Liz turn down before she finds her dream job?