Looking For Strange Algorithm For Frequency Rate Appearance Of An Object?

I've been racking my brain lately to try and come up with an algorithm to set a frequency rate at which an object may appear.

This best way I can think to describe a "for instance" is gonna sound nerdy but here goes.

Say I have a subclass that is just one of many on a Large class, kinda like spades in a deck of cards. However I dont specifically want 13 spades in my deck, I want to randomly generate this deck with a random chance of spade appearances. but beyond that, i want to give each sub-subclass, like a jack of spades, a "Frequency number", that upon generation of this main class (or deck in this example) will use random in combination with this "frequency rating" (0-100) to place the sub-sub class and even the sub classes in place.So as for my example, a 2 of spades might have a high freq like 90 and thus showed up 15 times in my deck, while the jack, with a rate of say 20, only showed up once or twice in my deck.