Beat Interview Brainteasers

Beat Interview Brainteasers

How to Answer Interview Brainteaser Questions

How many quarters -- placed one on top of the other -- would it take to reach the top of the Empire State Building?  

When Jeremy Solomon was asked this interview question, he didn't have a clue as to what would be the correct answer. Nonetheless, he remained calm.

First, he asked the interviewer exactly what she meant by "placed on top of the other." After she said on their sides, Solomon began to explain his logic step-by-step to the interviewer. He estimated that a quarter is about an inch in diameter and guessed that there are 120 floors in the Empire State Building, with each floor being 10 feet tall. Then he did the appropriate math.

Did Solomon give the right answer? Not quite -- the building only has 102 floors, and they aren't 10 feet tall.

Did he nail the question? Absolutely.

Divulge Your Thought Process

"Really, what interviewers are looking for is how somebody thinks through the problem," explains Jean Eisel, director of the Career Management Center at Duke's Fuqua School of Business. "Whether somebody gets the answer or not, it's more looking at how [job candidates] think through the problem. Don't try to get the answer. Focus on how you're going to divide the problem up. You don't necessarily have enough information to give the answer. They're really looking at how people process information."

The brainteaser is a type of interview question that's recently been popping up more and more. The use of these puzzling interview questions (how many times do a clock's hands overlap in a day? how would you weigh a plane without scales?) is originally attributed to Microsoft and made it's way into many technology companies' interviews. These types of questions have since been adopted by other industries, like business consulting, investment banking, law, marketing and finance.

There's even a book about this phenomenon, William Poundstone's How Would You Move Mount Fuji? The author offers similar advice to Eisel's: "They really expect you to walk them through your whole way of reasoning. And even if you end up not getting the right answer, they can be very impressed by some of the approaches you toss out there. In solving any real-world problem in business, you basically have to go through this process of brainstorming some ideas that aren't going to work out. So if you can show that you can do that -- even with one of these [mind-bending] problems -- that gives them a lot of useful information, even if you don't actually come up with the answer."

Talk It Out

Joel Spolsky is founder of Fog Creek Software and used to work as a program manager at Microsoft. He's used brainteasers at both companies, primarily as conversation starters. "The goal is to have an interesting conversation with the person and to try to see if they're smart through that conversation," Spolsky explains. "If you have an interesting conversation about certain types of topics with a person, you can determine if [he] is the type of person you want to hire. The questions are almost a pretext to having that conversation. If you have a conversation with somebody about the Backstreet Boys, you're not going to learn how smart the person is."

The truth is, a smart interviewer won't particularly care if you know how many piano tuners there are in the world or why manhole covers are round instead of square. What interviewers will care about is how you approach, analyze and break down a problem.