Title: 1. During the summer vacation, someone go on road trip planned to drive the same distance every day. If a car travels more than 19 kilometers per day than originally planned, its journey will exceed 2200 kilometers in 8 days; If a car travels less than planned 12km every day, it will take more than 9 days to travel the same distance. Find the original planned daily mileage of this car. 2. During the summer vacation, two parents planned to take some classmates on a trip. They contacted two travel agencies at the price of 500 yuan. After negotiation, the preferential conditions of travel agency A are that two parents will charge in full, students will be charged 30% off, and travel agency B will give parents and students 20% off. Suppose these two parents lead classmate X to travel, which travel agency should they choose? In order to attract students and increase box office income during the summer vacation, a cinema decided to pre-sell the student movie tickets used in July and August to urban primary and secondary school students in June. The price of each ticket is 1 yuan, and a movie ticket can be exchanged at any time on the same day. If there are five screenings a day in July and August, the average movie ticket will be 250 in 3 yuan each time, so as to ensure that the box office income will not be average. 4. An engineering team plans to build 6 kilometers of roads in 10 days. After 1.2km is completed two days before construction, the plan is changed, and the road construction task is planned to be completed two days ahead of schedule. How many kilometers of roads will be built every day in the next few days? 5. During blasting construction, the burning speed of the fuse is 0.8cm, and the speed of people escaping is 5ms. How long does the fuse need to be at least in order for the ignited soldiers to run to a safe area outside 100m during construction? 6. An engineering team stipulated that 300 earthwork should be completed in 6 days, and 60 earthwork should be completed on the first day. Now it has to be completed at least two days ahead of schedule, so how much more will it be completed every day on average? 7. It is known that Li Hong is three years older than Wang Li, and the sum of the ages of Li Hong and Wang Li is more than 30 and less than 33. Ask Li Hong's age. 8. A worker plans to process 408 parts in 15 days and 24 parts every day for the first three days. How many parts does he have to process every day in order to overfulfil the task within the specified time? 9. Wang Kai's home is 2. 1 km away from school. Now he needs to walk this road in 18 minutes. It is known that the walking speed in Wang Kai is 90 meters and the running speed is 2 10 meters. How many minutes does it take to ask Wang Kai? 10. Class A and Class B donations are equal, both above 300 yuan and below 400 yuan. It is known that Class A 1 person donated to 6 yuan, the rest to 9 yuan, Class B 1 person donated to 3 yuan, and the rest to 8 yuan. How many students are there in Class A and Class B * * * 1 1. The original price profit rate of a batch of fruits is 50%. After selling half of it, prepare to sell it at a discount as soon as possible. If the total profit is not less than 30%, how much discount can the remaining fruit get? 12. The school's electric classroom is going to burn a batch of computer CDs. If you burn in a computer company, you have to pay 8 yuan for each CD. If you rent a burner, in addition to renting 80 yuan, each CD is 4 yuan; If you buy your own burner, you need 450 yuan. In addition, the cost of each CD is also 4 yuan. Assume that X discs need to be burned, and find out the range of X satisfying conditions ① and ② respectively. Renting a burner is more economical than burning it in a computer company. Buying a burner is more economical than burning it in a computer company; How to compare buying a burner and renting a burner? 13. A city produces an average of 650 tons of garbage every day, which is treated by two garbage dumps A and B. It is known that yard A can treat 50 tons of garbage every hour, and the cost per ton is 10 yuan; Yard B can handle 60 tons of garbage per hour, and the cost per ton is 1 1 yuan. (1) If it is stipulated that the cost of garbage disposal in this city should not exceed 7,000 yuan per day, how long does yard A spend on garbage disposal every day? (2) If it is stipulated that the daily garbage disposal time in this city should not exceed 7 hours, and the cost should be saved as much as possible, what should be the daily garbage disposal time at Site B? 14. A clothing factory produces suits and ties. 200 yuan for each suit and 40 yuan for each tie. In the promotion activities, the factory offers two preferential schemes to customers. 1. Buy a suit with a tie; 2. Pay for the suit and tie at 90% of the marked price. A shop owner is going to buy 20 suits from a clothing factory and get an x(x20). Please help the store choose the most economical purchase plan according to the different situations of X. 15. Put some chickens in several cages. If there are four chickens in each cage, there is no cage for one chicken. If you put five chickens in each cage, there will be no chickens in one cage. How many chickens and cages are there? 16. A math contest was held in a middle school. There is one participant in Class A and Class B * *, in which Class A has an average score of 70, Class B has an average score of 60, and the total score of the two classes is 740. What are the number of participants in Class A and Class B respectively? 17. Someone left by bus 12 1 km, which took 3 hours. The first section travels 42 kilometers per hour, the second section travels 38 kilometers per hour and the third section travels 40 kilometers per hour. The third journey is 20 kilometers. How many kilometers are the first and second sections? 18. An orchard made an insecticide with sulfur, lime and water, including 2 parts of sulfur, 0 part of lime and 0 part of water. How many kilograms of sulfur does it take to make 520 kilograms of this insecticide? 19. Take out a part of apples from each kilogram of 0.8 yuan and a part of apples from each kilogram of 0.5 yuan. After mixing *** 15 kg, it is sold to 0.6 yuan per kg. How many kilograms do you need to take out from each of the two apples? 20. Someone rides a bicycle from place A to place B at a speed of 10 km per hour. When I came back, I walked 8 kilometers more than when I went because I had a detour. Although the driving speed has increased to12km per hour, it takes10min to find the distance between A and B (inequality group). The answers are: 1, 2x+3 > 0-3x+5 > 0 2, 2x 0 3, 5x+6 < 3x8-7x > 4-. 2X0 6、 1-X>0 X+23 X+2 3/2X-3 10、 1-3y+9 < 73.9 (7+x) < 44。 (3+8) x > 65.5-3/ 1 x>5 6。 1 1x-5x>3 7。 -3a-9a> 1 1 8。 -4a+9>6 9。 33x+33< 1 10。 5 B- 9 < 9b 1 1.6x+8 > 3x+8 12.3 x-7≥4x-4 2x- 19 < 7x+3 1. 13..3x-2(9-x)> 3(7+2x)-( 1 1-6x). 5438+05.2(3x)

(1) It is planned to rent eight trucks A and B to transport all the tents and food to the disaster area at one time. As we all know, Class A trucks can carry up to 40 tents and 10 food, while Class B trucks can carry up to 20 tents and 20 food. How many schemes does the Civil Affairs Bureau have when arranging two kinds of trucks, A and B? Please help design it.

(2) Under the condition of problem (1), if the freight of Class A trucks is 4,000 yuan each, the freight of Class B trucks is 3,600 yuan each. Which scheme does the Civil Affairs Bureau choose with the least freight? What's the lowest freight?

2. A school is going to organize 290 students to make a field trip, with luggage 100. The school plans to use 8 cars of two models, A and B. It is understood that A can carry up to 40 people and 0 pieces of luggage 10, and B can carry up to 30 people and 20 pieces of luggage.

(1) Rent X Class A cars. Please help the school design all possible car rental schemes.

(2) If the rental expenses of A and B are 2000 yuan and 1800 yuan respectively, please choose a more economical rental scheme.

1. If the tent is X, then X+(X-80)=320, and X=200, we can know that the tent is 200 and the food is 120. 1, and the first class is x, then 40x+(8-x) 20 ≥ 200,65438. B has five cars, or A has four cars, and B has four cars, which is 24000 x+3600(8-x)= 400 x+28800. Because 4≥X≥2, when X=2, the freight is the least, which is 29,600 yuan. Two schemes, 6≥X≥5 and * * *, are found, which are 5 A and 3 B, or 6 A and 2 B 2, 2000 X+1800 (8-X) = 200 X+14400 respectively. Because 6≥X≥5, it is more economical to rent a car when x = view/1d2c162fe2bd960590c677c7.html/view/125cfb770bf78a65295433.html Thank you! ! ! ! ! ! ! ! ! ! ! ! !