Find out the number of circles in the given picture having Illusion

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

What does this mathematical rebus means ?

In order to complete the racing competition, the Mexico racetrack has to submit its top and the most famous three horses to win the competition. Due to an electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the Mexico racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

Can you replace the question mark with the correct number?

I have Rs.50 and I spend it in the way as below.

What breaks yet never falls, and what falls yet never breaks?

A man was convicted of a minor offence in Akbar court. Akbar decided to give him a chance. He asked him to give a statement. If the statement is true, he will be killed by lions and if it is false, he will be killed by trampling of wild elephants.

The convicted person requested help from Birbal and since the crime was not a big one, Birbal decided to help him. Whatever Birbal suggested impressed Kabir and he let the convicted person go.

What did Birbal suggest to the person?

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