1, it always costs 700 yuan to buy tickets separately for three groups. If you buy them together, you will save 60 yuan, so the best price is 640/80=8 yuan/person.

Then, the teams that can be divisible by 8 yuan are the teams of 200 and 320, so Group B and Group C have already enjoyed the preferential treatment.

2. There are 25 people in Group B, 40 people in Group C and 80 people in Group A, so there are 15 people in Group A. That is to say, if there is no discount, everyone has to pay 12 yuan to buy tickets.