Logic Riddles

Question: How can a pants pocket be empty but still have something in it?

Question: Can you finish this pattern? j, f, m, a, m, j, j, a, s, o, n, _?

Question: John got trapped in a cage. His parent are going to be beheaded. And his girlfriend is next. Who will he save first?

Question: If Paul was born on September 17, 1948, then what year is Paul's birthday?

Question: Fifty is my first, my second is the third in fourth, and my end is the end of an ending. With a nut I become a nut that isn't, and without one I move.