This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

How many times can you subtract the number 5 from 25?

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

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?

In an office's desk, you find a unique method that shows the current day of the month. Two numbered cubes are used to depict the current date.

Can you find out the numbers on both the cubes so that each date can be mentioned using them?

Please note that you have to use both the cubes to display any date. Thus the 1st day must be represented by 01 and so on.

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

Find the number of squares in the below-given picture.

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

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