What is the word or phrase?

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?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

The more of this there is, the less you see. What is it?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

Replace the question mark with the correct number below.

Chocolate costs 6 rupees and a Toy costs 5 rupees. If you have 32 rupees in total, how many chocolates and how many Toys can be purchased with that amount?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

In the following picture, E is going to slide the object down and as per the terrain and the physics, the round object is going to travel all the way till the end. Now, can you analyze who all people will die when it happens?