why number 8549176320 is one of a kind?

Find the missing number in the image below.

Can you find out the number that should replace the question mark with a valid reason?

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?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

Can you decipher the below rebus?

PBLUESAISNUERSES

What does this rebus puzzle means ?