Good Riddles

Question:

You have a large number of friends coming over and they all get thirsty. Your first friend asks for 1/2 a cup of water. Your second friend asks for 1/4 a cup of water. Your third friend asks for 1/8 a cup of water, etc.

How many cups of water do you need to serve your friends?

Question: I'm measured in temperature and time, but have neither.

What am I?

Question: 7 months have 31 days. How many months have 28 days?

Question: Fast you travel, but I travel faster. The faster you travel, the further away I get still. Close as you may get, the faster I still will be. What am I?

Question: What starts with the letter "t", is filled with "t" and ends in "t"?