How can you tell a raw egg from a hard-boiled egg?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

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.

You can see three almost identical images below. Can you spot the odd one out from them?

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?