Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

What is the fastest way to double your money?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

Remove two matchsticks to make the below equation correct.

Jigsaw captured 100 people and make them stand in a circle and all these people are labelled as Person1, Person2, Person3... Person100. He made them play a crazy game in which Person 1 shot Person 2 and pass the gun to the next person and so on until one stands alive.

Which person will survive in the end?

I am sure no one can have two things for dinner. what are they?

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

What is more useful when it is broken?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?