Carl, who has been very sick is visiting his doctor to get the results of a battery of tests. "What are my chances of recovering, Doc?" he asks.
"One hundred percent," the doctor assures him.
"That's a relief," Carl says. "But how can you be so sure?"
"Well," the doctor says, "statistics show that nine out of every 10 patients with your disease will die. Yours is the 10th case I've treated. The others have all died. So you are bound to get well."