Logic Riddles

Question: Keys! keys! So many keys, When F is involved The key note is _ ?

Question: You have 20 sick sheep, one dies. How many are left?

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?