What has no start, end, or centre?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

The dirtier I get, the whiter I look. Who am I?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

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

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

If 21x = 79x, what is the value of x?