Bill Gates Sr. says his son -- the richest man in the world -- plans to give away his $100 billion fortune. Gates Sr. told the Sunday Times of London that Gates Jr. will reserve more than $20 million for his own son, then give everything else to the William H. Gates Foundation. Gates Sr. says one of his son's favorite books is Andrew Carnegie's "The Gospel of Wealth," in which the philanthropist wrote: "The man who dies rich dies in disgrace." Gates and his wife Melinda have already provided $10 billion for the Gates Foundation, making it the fifth largest philanthropic foundation in the world. The organization is committed to eradicating diseases such as AIDS and malaria.