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Four of the five tycoons atop Forbes magazine's list of the wealthiest people on Earth are self-made billionaires. The 2012 rankings size up 1,226 fat cats, according to net worth individually. Billionaire Li Ka-shing, pictured, made the top ten list - find out who came out ahead of him.
1. Carlos Slim Helu
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Mexican mogul Carlos Slim Helu tops Forbes' list of the richest people in the world for the third year in a row. The 72-year-old billionaire is the son of a Lebanese immigrant, a father of six and the chairman of Telemex, which controls 80 percent of Mexico's landline telephone market. Slim's net worth of $69 billion outranks the second wealthiest on the list by $8 billion, despite being down $5 billion from a year ago.
2. Bill Gates
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At $61 billion, Bill Gates is ranked No. 2 on Forbes' rich list. The 56-year-old tycoon dropped out of Harvard University in 1975 and co-founded Microsoft Corp. (MSFT). He's America's wealthiest person.
Bill Gates and his billionaire bud Warren Buffett have talked many of the world's wealthiest individuals into signing the "Giving Pledge," an effort to convince the richest people to give at least 50 percent of their wealth away to philanthropic causes.
3. Warren Buffett
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Third wealthiest on Forbes' list is the chairman and CEO of Berkshire Hathaway (BRK.A), Warren Buffett. He is arguably the most successful investor in the world. The 81-year-old "Oracle of Omaha" holds a Bachelor of Arts degree from the University of Nebraska, a Master of Science degree from Columbia University and has a net worth of $44 billion.
4. Bernard Arnault
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Bernard Arnault claims the No. 4 spot on Forbes' list of the world's wealthiest. The chairman of Louis Vuitton Moet Hennessy (LVMH) oversaw strong sales in 2011 of his company's lines of highly coveted designer goods, which boosted the company's profit 22 percent. His net worth of $41 billion makes the 63-year-old Frenchman Europe's richest person.
5. Amancio Ortega Gaona
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Seventy-five-year-old Amancio Ortega Gaona has a net worth of $37 billion, which makes him fifth on Forbes' list of the richest people. Spain's Ortega retired last year as chairman of Inditex, a global fashion firm and the parent company of Zara -- a tremendously popular chain of retail stores. Inditex shares in the past year have jumped roughly 25 percent. The boost in Inditex's market value pushed him into the top 5 of the world's wealthiest for the first time.
World's wealthiest people 2012
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Oracle CEO Larry Ellison, Brazilian billionaire Eike Batista, former H&M chief executive Stefan Persson, Chinese businessman Li Ka-shing and discount supermarket mogul Karl Albrecht make up the rest of Forbes' top 10 list of the world's wealthiest people for 2012. Click here to see the full list.