Complete the table series riddle by finding the number that can replace "??".

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

In a rainy season, one day 3 huge ladies walked under a normal-sized umbrella.
The umbrella is not huge enough to accommodate all 3 ladies yet not a single lady got wet. Why?

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

How is the moon similar to a dollar?

Can it be possible to build a house that has all its four walls facing towards the South?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

What does Alexander the Great and Winnie the Pooh have in common?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?