Find the value of "?" in the ball picture Riddle below:

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Can you find a rabbit in the given picture?

Through your logical capabilities, can you make 7 an even?

How many letters are in the alphabet?

What has many keys but can’t open a single lock?

Which number should replace the question mark?

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?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?