Can you convert the number zero(0) into a positive number using just one mathematical operator ?

10+10 and 11+11 can give you the same answer.

Explain how?

Joseph buys three kinds of chocolates for 100 rupees. The first one is priced at 5 rupees, second one at 3 rupees and third one at 0.5 rupees.

If he bought 100 chocolates in total, how many pieces do you think he bought each chocolate?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

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

Using Only Five 5's and any mathematical operator make sum as 37

When is the top of a mountain similar to a savings account?

A man is lying dead in a field where no one is around. His head is split open and his legs are disfigured. Near to him, there is an unopened package. No living organism can be found anywhere at the crime scene.

How did he die?

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.