What is the riddle which can be asked all day with a different correct answer each time.

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?

Solve the puzzle by telling what does below picture means.

Find the missing number: 1, 2, 3, 10, 10, ?, 9,802

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

How many bananas can you eat if your stomach is empty?

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

The Little ant seems to be always confused. Do you know why?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?