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

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

Keyboard words are not in alphabetical order, Why?

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?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

Below rebus represent famous DiCaprio movie. Can you name it?