Solution: 1 If it exceeds 100, the ticket price per person is 9 yuan, 1080/9= 120. According to the meaning of the question, there are not less than 20 students in grade seven and not less than 70 students in grade eight: 2 1x 15+99x65438+. 49x15+71x12 =1587, so the total amount of money bought separately should be in this range, and 1575 is there, so the assumption is correct, so the total number of people exceeds 100.

Let the seventh grade be x people.

15x+( 120-x)x 12 = 1575

X = the number of students in grade 45 is 120-45=75.

2. Set X yuan for Type A washing machine.

13% x+(x+500) 13% = 3 15

X=96 1.5 B type is 146 1.5.

Xiao Li: 961.5-961.5x13% = 836.51461.5-1463.5x13.

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