5. 12 After the Sichuan earthquake, Huaihua immediately organized medical staff to rush to the Sichuan disaster area to participate in the rescue of the wounded. It is planned to send 30 medical staff, carry 20 pieces of luggage (medicines and equipment), rent 8 cars of two models, A and B, and arrive at the disaster area day and night. It is understood that car A can carry up to 4 people and 3 pieces of luggage, and car B can carry up to 2 people and 8 pieces of luggage.

1) If you want to rent a car, please design all possible ways to rent a car.

2) If the rental expenses of car A and car B are 8000 yuan and 6000 yuan respectively, please choose the most economical rental scheme.

Solution: (1) If X cars of Class A are rented, then 8-x cars of Class B are rented.

4x+2﹙8-x﹚≥30

3x+8﹙8-x﹚≥20

Solution: 7≤x≤8.8

∵x is a positive integer,

∴ x = 7 or x = 8

So there are two schemes for renting a car.

① Rent 7 Class A cars, 1 Class B car. ..

② Rent 8 A-class cars.

(2) ① 8000× 7+6000× 1 = 62000 yuan

② 8000× 8 = 64000 yuan

Answer: According to the calculation, it is more economical to rent seven A-class cars and 1 B-class cars, which costs 62,000 yuan.