Replace the question mark with the correct number below.

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

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?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

How far can you walk into the woods?