When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Find the missing number in the image below.

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

What number comes next in the series?

5 15 5 18 5 24 14 20 _

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?

On a special event at the prison, 5 prisoners John, Jacob, Krist, Tang, and Dang given a chance to go to a sauna and can bring one thing with them.

Following are the things that the prisoners bring with them.
John: A soda
Jacob: Thermos
Krist: Book named "How to kill"
Tang: A Walkman
Dang: Harmonica

Since it is a Sauna, no one can see each other. After a while When the steam is switched, Tang was found dead and there was blood all around.
J Bond was called and he instantly come to know who can be the murderer. How?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

In the image given, you can find several triangles. Can you count them all?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?