Berkshire Hathaway Inc shareholders on Saturday celebrated Warren Buffett's 50th anniversary running the conglomerate, as the billionaire fielded questions about the company and its future, and explained some business practices. Berkshire owns more than 80 companies including the Burlington Northern railroad, Geico car insurance, Benjamin Moore paint, Dairy Queen ice cream, Fruit of the Loom underwear, and See's candies, and owns more than $115 billion of stocks.