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

What is always in front of you but can’t be seen?

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

What is the difference between a jeweller and a jailer?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

The more it dries, the wetter it becomes. Can you tell what it is?

Can you place six X (crosses) in below board without making three in a row in any way ?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?

If you paint a brown house white it will become a white house. If the stoplight changes from red to green, then the light is green. So, if you throw a white shirt into the Red Sea, what will it become?

Why did Navjot Singh Sidhu put the new January calendar in the freezer