Why do Chinese men eat more rice than Japanese men do ?

I am white when I am dirty, and black when I am clean. What am I?

What word begins and ends with an E, but has only one letter?

When can we add 2 to 11 and get 1 as the correct answer?

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?

What demands an answer, but asks no questions

What goes up but never comes down?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Find the next number in the following series:
6, 14, 26, 98, __?

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?