What number / letter should replace the question mark?

How many numbers do you see here?

What is the number of parking space containing the car?

Which tank will be full first?

Can you count the number of circles that contain a black dot?

If 3 cats can catch 3 bunnies in 3 minutes, how long will it take 100 cats to catch 100 bunnies?

I add five to nine and get two. What am I possibly talking about?

Your parents have six sons including you and each son has one sister. How many people are in the family?

How many times does the digit 5 occur in the numbers from 1 to 100?