Shamelessly poached from elsewhere:
Donald Trump was in Berlin for his first state visit with Angela Merkel. Trump asked her secret of her great success.
Merkel told him you just have to have a lot of intelligent people around you.
“How do you know if someone is intelligent?” asked Trump.
“Let me demonstrate.” She picked up the phone, called Wolfgang Schäuble and asked him a question, “Mr. Schäuble, it’s your father’s son, but not your brother. Who is it?”
Without hesitation, Schäuble answered , “Quite simply, it’s me!”
“You see,” Merkel told Trump, “this is how I test people’s intelligence.”
Thrilled, Trump flew home, and immediately called 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 said, @I have no idea, but I’ll try to find out the answer by tomorrow!" Pence just can’t figure it out and decided to seek advice from former President Obama, so he called him and said, “Mr. Obama, it’s your father’s son, but is not your brother. Who is it?" Obama answered, “Easy, it’s me!"
Happy to have found the answer, Pence called Trump and said triumphantly, “I have the answer, it’s Barack Obama!” Trump rages and says, “No you jackass, it’s Wolfgang Schäuble!”