I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

what one word does the below rebus identifies?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

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?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

What does this rebus riddle means ?

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

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

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

What has a bottom at the top?