Not difficult. The first question takes into account that Asian countries are not in the same group for three months. The first one can be randomly selected, 16, the second one can't be in the same group as the first one, only 4×3= 12, and the third one can't be in the same group as the first two, only 4×2=8.
The second question considers three groups. Similarly, the first one is randomly selected, and the second one is in a group with the first one, so 4- 1=3, the third one is in a group with the first two, and 4-2=2.