Can you make four (4) nines (9) equal 100?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

By moving just one matchstick, you need to make the below statement true. Can you do it?

Count the number of triangles in the below picture?

There is a certain crime, that if it is attempted, is punishable, but if it is committed, is not punishable. What is the crime?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

What is at the end of a rainbow?

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.

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?