If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

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

The captain of a ship was telling this interesting story: "We travelled the sea far and wide. At one time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly." How can that be possible?

Can you solve below mathematical equation?

2^1234 - 2^1233

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

When 99 is considered higher than 100?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

Can you find out the missing number in the grid?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?