Sunny Varkey

Dubai-based education entrepreneur sold a 20% stake for $350 million, in October 2014, in the emerging markets unit of his GEMS Education, the world's largest operator of private K&mdash;12 schools, to a consortium of investors, including Blackstone and Bahrain's sovereign investment arm. He stepped down as chairman, ceding spot to Sir Michael Peat, a former private secretary to Prince Charles. GEMS is now eyeing expansion in Africa and his native India, where, reportedly, it's bidding for Versity Education Management, an education services firm. <br> Varkey signed The Giving Pledge in June.