Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

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?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

what does the below math rebus puzzle mean?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?