Logic Riddles

Question: How can twins be born in different years?

Question: If there were ten fish in an enclosed tank, and four swam away, three died, and three drowned, how many fish would be left?

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: The more you add, the less it weighs.

Question: 2 men and a boy started a never ending race. One of the men can run super fast while the other man can run way faster than the boy. The boy is the slowest runner. What are they?