Who Is the Youngest US Dollar Billionaire?

Answer:

The youngest US dollar billionaire is Mark Zuckerberg (USA, b. 14 May 1984), who had an estimated net worth of $1.5 billion (£756 million) when listed on Forbes.com on 5 March 2008, aged 23 years 296 days.

Mr Zuckerberg is the CEO of the social networking site Facebook, which he founded in February 2004.