R. Wiski asks:
3 people from 3 different groups of 3 each combine to make a new group for zimun. That leaves 3 groups of 2. Do they combine into 2 new groups of 3 or are they left without zimun?
R. Wiski
The Kollel replies:
Yes, the people in the remaining groups also combine together to full their obligation of Zimun. When Rav Huna said in the Gemara that 3 who came from 3 groups of 3 each must do zimun, this is not necessarily referring only to the first set of 3 who combined. The second set of 3 from each of the 3 different groups also combine, and similarly the third set of 3 also must do Zimun.
Kol Tuv,
Dovid Bloom