A gun shots bullets with different speed each second.<br>
The bullets form a straight line.<br>
The bullets keep their speed (not getting slower or faster).<br>
But if 2 of the bullets collide, 2 of them are destroyed (annihilated)<br>
The gun stops after 12 bullets fired.<br>

**What is the probability that all the bullets will be destroyed ?<br>**

**There is a beautiful math formula for every even bullets fired, find it!**

>! This is a puzzle from a good website, I will show the link after the puzzle solved.<br>