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

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

What does this rebus mean?

O
N
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TIME

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Can you find the company name in the pictogram below?

Replace the question mark with the correct number.

What is black when you buy it, red when you use it, and gray when you throw it away?

Can you write down eight eights so that they add up to one thousand?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

How can you tell a raw egg from a hard-boiled egg?