What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

What type of tree can I carry in my hand?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

What have one eye but still cannot see?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

Which is the rope you never skip with?

If eleven plus two equals one, what does nine plus five equal?

What is common among 11, 69, and 88?

Can you name some countries which do not have the alphabet 'A' in them?