Can you place three balls such that the equation shown in the picture holds true?

There are forty elephants and they have forty-fore heads. How can this be possible?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

I have branches, but no fruit, trunk or leaves. What am I?

Why is a river so rich ?

Two friends were stuck in a cottage. They had nothing to do and thus they started playing cards. Suddenly the power went off and Friend 1 inverted the position of 15 cards in the normal deck of 52 cards and shuffled it. Now he asked Friend 2 to divide the cards into two piles (need not be equal) with equal number of cards facing up. The room was quite dark and Friend 2 could not see the cards. He thinks for a while and then divides the cards in two piles.

On checking, the count of cards facing up is same in both the piles. How could Friend 2 have done it ?

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

Take one out and scratch my head, I am now black but once was red. What am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?