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

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

Solve the equation in the image by looking at the pattern closely.

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

A Detective reviewed the information they had on the case so far.

A lady named 'Caterina' was found shot and they already had a list of suspects - Ankit, Tarun, Harish, Manoj and Manish.
The killer is a fan of challenges him by leaving notes ad various places.
* The first was found in a toilet room.
* The second was found in an art room.
* The third was in a restroom.
* the fourth in an underwater room.
* The fifth at the no-smoking room.

All of the notes read the same thing, 'The clues are where you find the notes.' Yet, nothing was found at any place the notes were.
Detective the genius, immediately solved the case.
Who was the killer?

How can one talk without saying a single word?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

You can hear me, but you can't touch or see me.

What am I?