George Bush meets the Queen in London, and this is how the conversation goes:

George Bush: Your majesty, you are one of the worlds great leaders, what's the secret on good leadership?

Queen: I surround myself with intelligent people! Here let me demonstrate.

(Her majesty picks up the phone and calls Tony Blair)

Queen: Hello Tony, if your mother has a child, your father has a child, and this child is not your brother or sister. Who is it?

Tony Blair: It's me your majesty.

Queen: That's correct, did you understand Mr Bush?

George Bush: Yes your majesty, I'll definately use that idea!

(So George Bush returns to washington, and decides to put Donald Rumsfeld to the test)

George Bush: Donald, if your mother has a child, your father has a child, and this child is not your brother or sister. Who is it?

Donald Rumsfeld: I'll do some research and get back to you.

(Donald Rumsfeld calls a big meeting with all the senior advisers but they cannot find the answer, so Donald calls Colin Powell)

Donald Rumsfield: Colin, if your mother has a child, your father has a child, and this child is not your brother or sister. Who is it?

Colin Powell: It's me stupid!!

(Donald runs back to George Bush)

Donald Rumsfield: Mr president! I know the answer! I know the answer! It's Colin Powell!

George Bush: Don't be stupid!! It's Tony Blair!!