DUH IX
From Reader's Digest

   Tourists at a natural history museum are marveling at some dinosaur bones. One of them asks a guard, "Can you tell me how old the dinosaur bones are?"
   The guard replies, "They're 65,000,011 years old."
   "That's an awfully exact number," says the tourist. "How do you know their age so precisely?"
   The guard answers, "Well, they were 65,000,000 years old when I started working here, and that was 11 years ago."