Can you find a five letter word that is left with only two letters if one is removed?

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?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

What makes this number unique: 8,549,176,320?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

Move three sticks of the spiral below to form a square.

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

By using 'because' continuously three times, can you make an English statement ?

What jumps when it walks and sits when it stands?