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

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

Which number should replace the question mark?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

Jigsaw captured 100 people and make them stand in a circle and all these people are labelled as Person1, Person2, Person3... Person100. He made them play a crazy game in which Person 1 shot Person 2 and pass the gun to the next person and so on until one stands alive.

Which person will survive in the end?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

What Adam and Eve do not have but the rest of the people have?

Why do Chinese men eat more rice than Japanese men do ?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?