What has one letter and starts with an E?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

I have an eye but still cannot see.

Who am I?

Buy me, smell me or deliver me, I do not change.

Who am I?

What you cannot hold but it is yours?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

You see me once in June, twice in November, and not at all in May. What am I?

Can you find the hidden animal in the picture below?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?