Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

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?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?

A sundial has the fewest moving parts of any timepiece. Which has the most?

What can you deduce from the following BrainBat?

CRY
LMKI

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?