Answer:
Adored by few, feared and hated by many. Mistress of the entire universal reason, master in the art of numbers. Some may have solved many of my mysteries, but there are still many of them to find. What am I?
What is black when it's clean and white when it's dirty?
I'm a kind of cup that doesn't hold water, but makes a lot of noise repeatedly. What am I?
Flat as a leaf round as a ring. I have two eyes but can't see a thing.
I hold two meanings. With one I may be broken, with the other I hold on. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.