Logic Puzzles #2

It's been a bit on the heavy side here lately - so for fun (OK, fun for math geeks like me!) here are a few of my favorite trick math questions. What I like about these is that even though you can get the right solution if you know some math, the answer still seems wrong to your common sense:

1) A string exactly encircles the entire earth at the equator. It is cut at one point and one extra yard of string is added. How high off the ground can you now place the string?

2) If you fold a paper in half 50 times, about how thick would the wad of paper be?

3) If you invested a penny in the year 1 CE at 5% annually compounded interest, how much money would you now have?

4) If a waterlily doubles in size every day and takes 30 days to fully cover a lake, how long would it take two such waterlillies to cover the same lake?

5) A hobo collects cigarette ends and can make one cigarette from four ends. He has 11 ends; how many cigarettes can he make and how many ends will be left over?

That's all for now. We're off to Baltimore this weekend for a family reunion of sorts; my sister and family and my mom live there, and my brother and family are in from Israel. Have a good Shabbos/weekend!