Why are Manholes Round? The 10 Toughest Interview Questions

by Meghan Casserly, courtesy of Forbes.com 

A job interview at one of Google’s 75 campuses around the globe might seem to have more in common with pledging a secret fraternity than job-hunting. An often months-long interview process, iron-clad non-disclosure agreements and back-to-back hours of interrogation in windowless offices are a matter of course, but the added intrigue of allegedly absurd interview questions takes the experience into cloak-and-dagger territory.

Why are manhole covers round? How do you measure 4 gallons of water using only a 3 and 5 gallon jug? How many gas stations/dogs/windowpanes are there in the United States? According to career communityGlassdoor.com, these are a few of the more obscure queries asked of wannabe Googlers.

You have to give it to them, the questions are creative. But are they effective in finding the right candidate? And more importantly, will answering them correctly land you a job?

“This kind of question is used to determine poise and the ability to think on one’s feet,” says Dale Austin, director of career services at Michigan’s Hope College. “But also to assess creativity and problem-solving.” In other words, Google is looking for a quick answer that proves you’re not only agile but logical, adaptable and math-minded.

That’s all well and good for the analytical minds of Googlers, but veteran Bay-area executive headhunterChuck Pappalardo says it really all depends on what you’re looking for. For Google, whose ranks Pappalardo describes as “engineer from top to bottom,” they can prove telling. “These kinds of questions measure whether someone can work in the crazy environment [of a young tech firm] and have the right engineering background to make them a good employee. They show quick, analytical thinking, and the ability to pivot.”

But what these “trick” questions can’t highlight is a quality that Pappalardo sees as not only more human, but more vital to the majority of careers–positions where customer or client interaction is essential. That quality? Integrity.

“A good interview requires more than just good questions. It also requires a deep understanding of the traits and behaviors you’re seeking or avoiding,” he says. “By crafting questions designed to elicit “evidence” of the desired characteristics, you’re able to draw conclusions about candidates’ ability to perform in an authentic and meaningful way.”

Fine, if you’re on the questioning side of the desk. But for those of us in the hot seat, prepping for questions designed to “elicit characteristics” can be quite tricky. Pappalardo concedes they can be among the most difficult to answer, because they require much more than rattling off resume points. Here, the 10 toughest—but most telling– interview questions, and best of all…how to answer them.

Read the questions and learn the reasoning behind them here.