In the new study, Oxfam, get coverage in The Guardian, scientists have found out how many years you will need the richest people of the world to spend all the money. Bill Gates spent their 79 billion US dollars for 218 years. This is equivalent to the purchase of three "Ferrari" in the day. "The King," communications industry Mexican Carlos Slim "stretch" and even longer - 220 years. American investor and businessman Warren Buffett earned slightly less - only 169 years.