Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

What is the riddle which can be asked all day with a different correct answer each time.

Can you count the number of squares in the given picture?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

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

Find the next number in the series.
1 10 24 43 67 ?

What begins with T, ends with T, and has T in it?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)