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?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

What always comes into a house through the keyhole?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

What Time Should the last watch show in the below figure?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

What goes through cities and fields, but never moves?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

If eleven plus two equals one, what does nine plus five equal?