Do you agree to this fight?: Musk to Putin after challenging him to single combat for Ukraine

World's richest man Elon Musk on Monday in a tweet tagged the President of Russia's official Twitter account and asked, "Do you agree to this fight?" In an earlier tweet, Musk had said, "I hereby challenge Vladimir Putin to single combat...Stakes are Ukraine." When a Twitter user asked, "Did you think this through?", Musk responded, "I am absolutely serious."