Answer:
I'm pretty sure the answer is 6.
Step-by-step explanation:
Labeling the rooms A, B, and C makes it easier.
Room A - All BUT 4
Room B - All BUT 4
Room C - All BUT 4
Since you can see each room is all but four, you can split the 4 into 2 into 2 OTHER rooms than the one stated. For example, Room A is all but 4, so 2 go to Room B and the other 2 go to Room C because each room is all BUT 4.
Basically, 2+2+2 = 6