What always comes into a house through the keyhole?

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

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

What does this Rebus Picture mean?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

Take away the whole and some still remain. What is it?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

What's a single-digit number with no value?