(Zigong, Sichuan 2065438+8, 2003) A school has several dormitories for students. According to statistics, there are 740 senior three boys in this school, with 55 rooms.

Solution: (1) There are X people in each dormitory of this school and Y people in each dormitory.

,

Solution:.

A: There are 8 people in each big dormitory and 6 people in each small dormitory.

(2) If there is a big bedroom, there are (80-a) small bedrooms.

, the solution is: 75≤a≤80.

∫a is an integer,

∴①a=75，80 ? 75 = 5，②a=76，80 ? A = 4

③a=77，80-A = 3，4A = 78，80-A = 2，

⑤80﹣a= 1 a = 79，⑤﹣a = 80，80 a = 0。

* * * There are six accommodation arrangements.

(1) First, let's set X people in each big bedroom and Y people in each small bedroom. Focus on the statement, "There are 740 boys in Grade One, 55 large bedrooms and 50 small bedrooms, which are just full; 730 girls, with 50 big bedrooms and 55 small bedrooms, just full. Just list the equations.

(2) If there is room A in the big dormitory, it can be found that room A in the small dormitory (80-a) is a≤80, and then according to the key sentence "No less than 630 girls in Grade One will live in 80 dormitories", the inequality 8a+6 (80-a) ≥ 630 can be found, and the inequality group can be solved.