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?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Forwards I am heavy, backward I am not. What am I?

what's the probability of getting a king or a queen from a pack of 52 cards?

I have an eye but still cannot see.

Who am I?

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

What have one eye but still cannot see?