Donald Trump & Angela Merkel in Berlin

Donald Trump is in Berlin for his first state visit with Angela Merkel. Trump quickly asks what the secret of her great success is.
Merkel tells him you just have to have a lot of intelligent people around you.
“How do you know so quickly if someone is intelligent?” asks Trump.
“Let me demonstrate.” She picks up the phone, calls Wolfgang Schäuble, and asks him a question, “Mr. Schäuble, it’s your father’s son but is not your brother. Who is it?”
Without hesitation, Schäuble answers, “Quite simply, it’s me!” “You see,” Merkel tells Trump, “this is how I test people’s intelligence.”
Thrilled, Trump flies home, immediately calling his running mate, Mike Pence, to ask him the same question. “It’s your father’s son but is not your brother. Who is it?”
After much back and forth, Pence says, “I have no idea, but I will try to find out the answer by tomorrow!” Pence just can’t figure it out and decides to seek advice from former President Obama. He calls him, “Mr. Obama, it’s your father’s son, but is not your brother. Who is it?” he asks Obama. “Easy, it’s me!”
Happy to have found the answer, Pence calls Trump and says triumphantly, “I have the answer, it’s Barack Obama!” Trump rages and says, “No you jackass, it’s Wolfgang Schäuble!”