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

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

What kind of tree can you carry in your hand?

A man looks at a painting in a museum and says, “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the painting?

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

Which alphabet letter is a question?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

A very interesting trivia question for all.

Why do men's shirts have their buttons on the right side and women's have buttons on the left-hand side?

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.