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: .<br>Interviewing with Elon Musk is not for the faint of heart. Musk, the chief executive of Tesla and SpaceX, is known to appear disinterested in candidates at first .<br>The engineer-magnate is a co-founder of electric-car maker Tesla Motors. Elon Musk will now take your questions.<br>At the International Astronautical Congress, SpaceX CEO Elon Musk unveiled his ambitious plans for interplanetary travel. Afterwords he fielded some very .
