What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

During which month do people sleep the least?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

Name a key which is hardest to turn.

Find the last number in the series below:

voN luJ yaM raM ---

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?

What is both possible and impossible at the same time?