What number when divided in half becomes zero?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

Three people enter a room and have a green or blue hat placed on their heads. They cannot see their own hat but can see the other hats.
The colour of each hat is purely random. They could all be green, blue, or any combination of green and blue.
They need to guess their own hat colour by writing it on a piece of paper, or they can write 'pass'.
They cannot communicate with each other in any way once the game starts. But they can have a strategy meeting before the game.
If at least one of them guesses correctly they win $10,000 each, but if anyone guesses incorrectly they all get nothing.
What is the best strategy?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

What does this Rebus Picture means ?

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