The world’s two richest men, Bill Gates (left) and Carlos Slim, seen at an event in Texcoco, Mexico, on February 13, 2013, are occasionally teaming up in their philanthropic ventures. (Tim Johnson/MCT via Getty Images)
The world’s two richest men, Bill Gates (left) and Carlos Slim, seen at an event in Texcoco, Mexico, on February 13, 2013, are occasionally teaming up in their philanthropic ventures. (Tim Johnson/MCT via Getty Images)