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?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

What is black when you buy it, red when you use it, and gray when you throw it away?

Five teams were competing in cricket where they faced each other exactly once. After the tournament, the following is the point table.

DareDevils 6
SuperKings 5
Royals 4
Sunrisers 2
Riders ?

How many points did Riders end up with?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Can you find out the number that should replace the question mark with a valid reason?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)