How to answer Elon Musk's favorite job interview question

SpaceX CEO Elon Musk likes to ask one riddle in particular when interviewing candidates for a position with his company, according to the book "Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future." The question has two answers -- one simple, and one slightly more complicated.Here's the question -- and the answers. Do you have what it takes to work forMusk? Follow Tech Insider: On Facebook