why number 8549176320 is one of a kind?

If a wheel has 54 spokes, how many spaces are there between the spokes?

The centre of the third figure is empty. What digit should fit inside?

What is the centre of gravity?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

What can you see in the middle of March and April that you can never see in any other month?

What is the fastest way to double your money?

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?