Why are Manhole Covers Round?

Last fall I read the book on how Amazon grew into the giant that it is today. Part of the story focussed on how Amazon hired new employee’s, with the mantra of “only hiring the absolute best and smartest out there”. This included unorthodox interview questions such as “Why are manhole covers round?”
The character trait that Jeff Bezo’s was looking for was fast thinkers and problem solvers. He was drilling down to how the candidates thought process worked, specifically their deductive reasoning and lateral thinking skills. Growing your business takes systems but ultimately it takes great people to develop and work within systems to be successful. Focus on the people that you surround yourself with to make a real difference in your business.

Other typical questions they use:
How many times a day does a clock’s hands overlap?
How many golf balls can fit in a school bus?
Explain a database in three sentences to your 8-year-old nephew.

By asking brain teaser questions, Amazon got a first-hand look at what type of person they were recruiting and allowing into their business.  The next time you recruit into a new position what questions will you ask?