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How To Hire People Smarter Than You. . .Or. . .Why Are Manhole Covers Round?

August 22, 2019

Microsoft was famous for them, obscure interview questions. Things like, “How do they get the colors on M&Ms?” or “How many gas stations are there in the United States?”

The purpose of these obscure questions was to try to figure out how people think. I mean, you can’t just ask someone, “How does your brain work out complex problems?” But, that’s what they are trying to figure out.

I was once asked “How would you design a logic system for an elevator?” “What if there were two elevators?”

As manager of technical teams, I have also attempted to hire people smarter than me. If you find yourself as the smartest person in the room, you are in the wrong room. But, how do you interveiw someone, hire someone who’s smarter than you are? Won’t they just be able to snow you with their answers?

That’s where the obscure questions come into play. It’s not about finding the right answer. It’s about finding the answer. For example, when asked about the number of gas stations, how do you approach it? You think about what you do know. How many people? (About 330 million) How many families? (Maybe 100 million) How many cars per family? (Two?) How many miles does each car drive per year? (12,000-15,000.) How many miles per gallon? (20?) So, how often will each car need to fill up? (math goes here) How many cars can use each gas station? (6-12)

And eventually you have a number for how many gas stations there are in the United States. It doesn’t really matter what the right answer is. It matters how you got to your answer.

The most famous question, in my experience, had to be the manhole cover question.

Why are manhole covers round?

Over the years I heard four possible answers.

First, that’s what the designers chose. Since manholes are round, designers chose to make the covers round. They could have chosen squares, or triangles, or a rombus. But, they chose circles.

Second, (and a bit of more of a practical answer) the deisgn prevents the cover from falling into the hole. It’s impossible for a perfectly round manhole cover to fall into the manhole.

Third, they are easier to move. Manhole covers are very heavy. However, making them round means a single person can move it by rolling it on its side.

And finally, it’s the most efficient. A round cover means that it makes the most efficient use of materials.

Microsoft eventually moved away from the weird, obscure questions. The stated reason was that they were becoming too well known. And maybe that was the case.

I’ve often, in fact, always, tried to hire people smarter than I am. I’ve even at times asked people to explain the logic of manhole covers.

Rodney M Bliss is an author, columnist and IT Consultant. His blog updates every weekday. He lives in Pleasant Grove, UT with his lovely wife, thirteen children and grandchildren.

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(c) 2019 Rodney M Bliss, all rights reserved

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