Riddle #199

Question: What is 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 10,000?

Question: What tastes better than it smells?

Question: What loses its head in the morning and gets it back at night?

Question: What two things can you never eat for breakfast?

Question: What asks but never answers?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?