What is always in front of you but can’t be seen?

Can you decipher the below rebus?

PBLUESAISNUERSES

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

There are two guys standing face to face in a room. On a wall, there is a clock. One of those is a prophet. He tells the other guy that he will be stabbed in the back in five minutes.

Shocked to hear that, the other guy stares at the clock. Just after the five minutes, he is stabbed on the back. Can you tell what happened?

Can you identify the hidden rebus in the image below?

Count the Triangle in the figure given below:

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

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

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?