Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

What word does this rebus represent?

meta meta
meta meta

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Consider this about a word: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

A man dies of old age on his 25 birthday. How is this possible?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

On a bright sunny day, two fathers took their son fishing in the lake. Each man and son were able to catch one fish. When they returned to their camp, there were only three fishes in the basket. What happened?

PS: None of the fish were eaten, lost, or thrown back.

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?