Complete the table series riddle by finding the number that can replace "??".

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

Can you count the number of triangles inside a triangle?

What's a single-digit number with no value?

What does this rebus riddle means ?

What is harder to catch the faster you run?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

Bay of Bengal is in which state?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

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?