What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

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

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?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Look at the picture and find out which square is not linked with any of the other squares.

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

Can you find the number?

Find the last number in the series below:

voN luJ yaM raM ---

A bank customer had $100 in his account. He then made 6 withdrawals. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

Withdrawals Balance left
$50 $50
$25 $25
$10 $15
$8 $7
$5 $2
$2 $0
----- -----
$100 $99

Why are the Totals not tallying?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?