Class 5 (1) and class 5 (2) go to the park. The park ticket is 5 yuan per person. The group ticket for more than 30 people (including 30 people) is 3 yuan per person. Class 5 (1) and class 5 (2) are less than 30 people, and the number of students is equal. So the two classes together buy group tickets, which saves 100 yuan How many people are there in each class? 2. How much did the ticket cost?

Class 5 (1) and class 5 (2) go to the park. The park ticket is 5 yuan per person. The group ticket for more than 30 people (including 30 people) is 3 yuan per person. Class 5 (1) and class 5 (2) are less than 30 people, and the number of students is equal. So the two classes together buy group tickets, which saves 100 yuan How many people are there in each class? 2. How much did the ticket cost?

1. Because the number of people is equal, so (2x) * 5 = (2x) * 3 = 100, x = 25, there are 25 people in each class
2. A total of 50 people, so it cost 150 yuan to buy tickets

A tour group has 51 people to stay in a hotel, two rooms are 80 yuan per night, and three rooms are 90 yuan per night. If the tourists just live in 21 rooms, how many rooms are there? How much is the tour group's cost for one night? Quick, good people live a hundred years. Thank you!

Suppose that x is between two people and Y is between three people, then
x+y=21
2x+3y=51
The solution is x = 12, y = 9, and the cost is 80 * 12 + 90 * 9 = 1770