Intelligence test

Fuckwit David Harrison was visiting the Eastbourne and Country Taxis company and 
happened to meet with the managing director.  Fuckwit said, "I'm thinking of 
starting a houseboat cleaning company back at Holiday Marina.  Your company 
seems to run very efficiently.  What's the secret to your success?"  The 
director replied, "You must surround yourself with intelligent people."  Fuckwit 
said, "Okay, but how do I know if the people I hire are intelligent?"  The 
director answered, "You must pose a question to them that allows them to prove 
their intelligence.  Watch - I'll demonstrate."  He pushed the button on his 
intercom to the cabbies' lounge and said, "Please send Derek Nash into my 
office."  Derek appeared a moment later, and the director asked him, "Derek, 
your parents have a child, and it's not your brother and it's not your sister. 
Who is it?"  Derek answered promptly, "It would be me, of course."  "Very good," 
the director said, and Derek returned to the lounge.  Fuckwit was impressed. 
"Thanks a lot for that.  I'll use it when I get back to Lake Lanier."

When he returned, Fuckwit called Douchebag Ron Hamilton into the shack serving 
as an office and put him to the test.  "Uh...your parents have a child, and it 
ain't your brother and it ain't your sister.  Uh, who is it?"  Douchebag thought 
for a moment but couldn't answer.  "Boss, I'll have to get back to you on that," 
Douchebag said as he sidled out of the shack.  He asked all his pals but they 
couldn't answer, either.  Then he thought, "Rupert's the smartest 'vegan' I 
know.  I'll bet he knows the answer!" Douchebag looked up the University of 
Münster mathematics department and called it, eventually reaching Rupert. 
Douchebag said, "Listen, Rupert - your parents have a child, and it's not your 
brother and not your sister. Who is it?"  Rupert quickly replied, "Why, it's me, 
naturally!"  "Thanks, buddy, I owe you one," said Douchebag as he hung up the phone.

Douchebag raced back to the shack and said, "*Goo*, I know the answer to your 
riddle.  It's Rupert McCallum!"  Disgusted, Fuckwit slammed down a dirty mop and 
shouted, "No, you stupid fuckwit - it's Derek Nash!"