Tomorrow's math exam in the first day of junior high school, the finale will be explained in detail, and the important process will be sought after! ! !

(1) solution; Car X is needed to set up car B, and car 10-X is needed to set up car A;

{40( 10-X)+30X≥320

{ 16( 10-X)+20X≥ 170

Solve; 8≥X≥2.5 can be understood as 8≥X≥3, that is, the scheme is;

The vehicles are: when there are seven. , 6, 5, 4 and 3 cars. There are 5 combinations of 3, 4, 5, 6 and 7 cars in Class B. ..

(2),

According to the rental price, it is the most economical to use A-class cars as little as possible.

3× 2000+7×1800 = 6000+126000 =132000 (yuan)