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

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Find the number of squares in the below picture

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Can you solve this picture maths equation?

If your uncle’s sister is not your aunt, what relation is she to you?

You are given 2 eggs.
You have access to a 100-storey building.
Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor, Both eggs are identical.
You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?