2.(20 1 1 Chongqing Qijiang, 25 10) In order to protect the environment, a chemical plant purchased three A-type and two B-type sewage treatment equipment after the completion of the first phase of the project, which cost 540,000 yuan, and the price of each B-type equipment was 75% of that of each A-type equipment. In actual operation, it is found that each type B equipment can treat sewage 160 tons per month, and the annual maintenance and electricity charges for each type A equipment are 10000 yuan, and the annual maintenance and electricity charges for each type B equipment are 15000 yuan. This year, the second phase of the plant is about to be completed, and the sewage generated will increase greatly. Therefore, the plant decided to purchase eight A-type and B-type equipment for the second phase.

(1) Please calculate the price of each A device and each B device.

(2) Please find out the procurement scheme of all sewage treatment equipment in the second phase project;

(3) If the service life of both kinds of equipment is 10 year, please explain which procurement scheme has the lowest total cost among all the schemes in (2)? (Total cost = equipment purchase fee+various maintenance fees and electricity charges)

Answer: 25. Solution: (1) Suppose the price of type A equipment is X million yuan. It is found from the question that X = 12, ∫ 12×75% = 9, ∴ the price of a type of equipment is 120,000 yuan, while one.

(2) in the second phase of the project, buy a set of A equipment, which means:

There are four purchase schemes, namely ∴ A = 1, 2, 3, 4 ∴.

Scheme 1: 1 set of type A and 7 sets of type B; Option 2: 2 sets of A and 6 sets of B.

Scheme 3: 3 A and 5b; Option 4: 4 A and 4 b.

(3) The total cost of sewage treatment in phase II project 10 is 10,000 yuan.

Simplified: -2a+ 192,

∫w decreases with the increase of A ∴. When A = 4, w is the smallest (check one by one is also acceptable).

∴ According to Scheme 4, the total cost of purchasing 4 sets is the least.