Charlie went to his doctors for a Colonoscopy appointment, he was duly booked in and while he was waiting in the surgery waiting room he browsed the notice the board where he saw a line stating to ask about Mental deficiency testing. He was a little intrigued by this and thought to himself, I must ask the doctor about this.

When the nurse came out and beckoned him to come in “Would you mind telling me, Doctor,” Charlie asked, “how you detect a mental deficiency in somebody who appears completely normal?”

“Nothing is easier,” he replied. “You ask the person a simple question which everyone should answer with no trouble. If they hesitate, that puts you on the track.”

“What sort of question?” Charlie asked.

“Well, for example , Captain Cook made three voyages around the world and died during one of them. Which one?”

Charlie thought for a moment, and then said with a nervous laugh, “You wouldn’t happen to have another example would you? I must confess I don’t know much about history.” The doctor sighed.