Not-So-Dangerous Operation
When you want good odds, have this Doctor operate on you...

The doctor explained to Jenkins that he had a serious ailment for which an operation was absolutely imperative.

The patient turned pale and asked, “Isn’t it very dangerous?”

“Yes,” the doctor replied. “Five out of six who undergo this operation die, but as for you, you have nothing to worry about.”

“Why not?” eagerly inquired the patient.

“Well, you’re sure to recover because my last five patients died,” the doctor reassured him.