What does this rebus mean?

O
N
C
E
TIME

Can you count the number of matches in the picture below ?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

Why do you find that most of the buildings are deprived of the 13th floor?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

A container contains 100 eggs. They can be either fresh or rotten. What is sure is the fact that there is at least one fresh egg in that container.

If you are asked to pick two eggs randomly from the container, at least one of them will be rotten.

Can you calculate how many eggs in that container are fresh?

If eleven plus two equals one, what does nine plus five equal?

A Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?

What does below pictogram mean?

Why is it against the law for a man living in Delhi to be buried in Mumbai?