I need help trying to figure out how many breeding colonies i need to sustain my snakes....

I have over 50 now since i picked up a collection it came with a small breeding set of rats not sustainable for all the snakes. Basically this is what i need a week:

10 large

20 medium

20 small

How many colonies of rats do i need??? I usually do a 1.4 on mice and rats. So how many colonies?? i also have an ingenius plan on breeding them but if you want to find out you'll have to PM me lol PLEASE HELP give me an estimate!!!