How to rhythm that mechanism? They installed a machine surrounded by the local convenience shop, it drops...

They installed a machine surrounded by the local convenience shop, it drops out balls if you drop contained by money. They are different: transparent, coloured, multicolored and so on. Transparent are my favourites, they are "filled" with "water", and near are these bubbles inside, and they are white, bluish, greenish. But they fall out at all over the place.
How can I fix it so that only transparent ones fell out? You can see them losing the glass, contained by a bowl.
How do I determine what I inevitability to...
Answers:    figure out who fill the machine & ask them to go you a couple of them.