Suppose the number of China team is 1, and the others are 2, 3 and 4 respectively. Then * * * there are games 12, 13, 14, 23, 24, 34, which means 3+2+ 1=6 games. Including China, it is 12,13,655. So * * * six games, China three games. I hope I can help you O(∩_∩)O~