That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

When it is alive we sing, when it is dead we clap our hands. What is it?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?