why number 8549176320 is one of a kind?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

I have eight fingers and two thumbs but I do not live. What Am I?

What can you deduce from the following BrainBat?

CRY
LMKI

A man embarked on a questionnaire game. He kept asking the same question to whomever he found. The answer each time was different.

Can you guess what the question was?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

Solve the equation in the image by looking at the pattern closely.

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.