Expected number of randomly tied strings

Question: You have a bag with 'N' strings in it. You randomly grab two ends and tie them together until there are no more loose ends.

In the end, what is the expected number of loops (strings tied to their own end)?

Question: What is the next sequence of numbers and why? 1 11 21 1211 111221 312211

Question: I'm 10 years old my brothers half my age now I'm 100 years old how old is my brother now?

Question: Surrounded by life , yet life is its biggest enemy. But without life there is no need for it to exist. What is it?

Question: During what month do people sleep the least?

Question: A horse jumps over a castle killing a woman, who is she?