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

If 21x = 79x, what is the value of x?

Imagine you are in a room with no windows or doors. How will you get out?

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

A crime was committed at baker street. Ibrahim Dakota who was shot in the stomach was the main suspect. Sherlock questioned the suspect. The conversation started as:
Sherlock: What's your story, Ibrahim?
Ibrahim: I was walking around baker street and suddenly a man from the back shot me. I ran as fast as I could to save my life".
Sherlock: That is enough (and ask the police to arrest him).

Why does Sherlock think he is the murderer?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

Count the squares in the matchstick puzzle below?

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