In the activities of building a livable this beautiful city and a happy city, two engineering teams, A and B, bid for the city beautification project. After calculation, they got the following results

In the activities of building a livable this beautiful city and a happy city, two engineering teams, A and B, bid for the city beautification project. After calculation, they got the following results. (1) It will take X days for Group A to complete this project alone.

According to the meaning of the question, have to? ( 1x+ 1 60)× 16+ 1 60×20 = 1，

Solve this equation and get x=40.

X=40 is the solution of the original equation.

∴: Team A needs 40 days to complete this project alone;

(2) Assuming that the cooperation between Party A and Party B takes y days, there is (140+160) y =1.

Solution: y=24 (days),

The project cost paid by Party A alone is 40×3.5= 140 (ten thousand yuan).

B single completion exceeds the planned number of days and fails to meet the standard (no penalty will be deducted for not writing this line).

The project cost that Party A and Party B should pay is 24×(3.5+2)= 132 (ten thousand yuan).

A: Under the premise of not exceeding the planned number of days, the cooperation between Party A and Party B is the most economical.