Can you solve the below tricky visual equation?

On a special event at the prison, 5 prisoners John, Jacob, Krist, Tang, and Dang given a chance to go to a sauna and can bring one thing with them.

Following are the things that the prisoners bring with them.
John: A soda
Jacob: Thermos
Krist: Book named "How to kill"
Tang: A Walkman
Dang: Harmonica

Since it is a Sauna, no one can see each other. After a while When the steam is switched, Tang was found dead and there was blood all around.
J Bond was called and he instantly come to know who can be the murderer. How?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

What is the word or phrase below?
R | E | A | D

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

The husband and wife were jogging in the morning. To match every two steps of the husband, the wife required three steps. If Both of them start with the here right foot. After how many steps do their left foot be together?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.