In the first method, everyone buys tickets separately, and the cost of a ticket is * *1* 30+7 *15 = 435 yuan.

The second method, 10 adults buy, and the rest are purchased separately. The cost is10 * 30 * 0.7+30+7 *15 = 345 yuan.

In the third method, three adults and seven students buy collectively, and the rest buy separately.

Need (3 * 30+7 *15) * 0.7+8 * 30 = 376.5 yuan.

We can see that the second one is more suitable.

2. There are 7 adults and students 1 1 person.

In the first method, everyone buys tickets separately, and a * * ticket costs 7 * 30+11*15 = 375 yuan.

The second method, 10 students buy in groups and the rest separately, requires10 *15 * 0.7+15+7 * 30 = 330 yuan.

In the third method, three students and seven adults buy collectively, and the rest buy separately.

Need (3 *15+7 * 30) * 0.7+8 *15 = 298.5 yuan.

We can see that the third one is more suitable.

In other words, it is more appropriate to buy in a group that spends a lot of money.