This one is very well known, no riddle, just simple logic:
John and Jack go into a restaurant, the waiter comes to the table and asks:
"Sorry, you are both very alike are you gentlemen brothers?"
To which John replies:
"No we aren't, I have no siblings, the father of this fellow here with me is the son of my father."
What is Jack to John?
John and Jack go into a restaurant, the waiter comes to the table and asks:
"Sorry, you are both very alike are you gentlemen brothers?"
To which John replies:
"No we aren't, I have no siblings, the father of this fellow here with me is the son of my father."
What is Jack to John?