How many kids per provider?

Hi
My son is 3 and in an 'early preschool' program at a daycare. Generally the routine is that if they arrive before 8AM all the kids go into a large room until their teacher(s) arrive and they break out into their age groups. My concern is that this morning my husband went to drop him off and it was 8:50 and there was a larger than usual group of kids (approx 30 or so kids, including some 7 and older) in that room w/ only one adult in there serving up their breakfast.

So what is the rule about number of kids in that situation for each adult? I'm in Virginia and I know for his age it's 1-10 in a classroom but what about this particular situation? Does that same rule rule apply?

For the record, I called my Dad and had him go and pick up my son right away. It turns out both of my son's regular teachers are out today. It didn't sound like they were prepared to handle that.