If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

Can you count the number of matches in the picture below ?

I am sure no one can have two things for dinner. what are they?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

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?

When it's bad luck to meet a black cat?

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?