The shop bought 200 bicycles at the purchase price of 250 yuan and sold them at the price of 275 yuan each. Two months later, the sales of bicycles have exceeded the purchase of these bicycles. How many bicycles should be sold at least at this time?

2

In June this year, the students of Grade 3 1 Class took a group photo after graduation. To take a wide color group photo, you need to pay the film fee and photographer's labor fee totaling 58 yuan; Printing a color photo requires 3.5 yuan. Each student subscribes to 1 photo and presents 6 alma mater as gifts. Results The students who participated in the group photo did not share more expenses than 5 yuan. How many students took part in the group photo?

three

A factory has 360 kilograms of raw materials A and 290 kilograms of raw materials B, and plans to produce 50 products A and B with these two raw materials. It is known that 9 kg of raw material A and 3 kg of raw material B are needed to produce a product A; It takes 4kg of raw material A and10kg of raw material B to produce Class B products. ..

1, suppose X pieces of A product are produced, and write the inequality group that X should satisfy.

2. What kinds of production schemes are there? Please help design.

four

A garment factory currently has fabrics A 70M, B and 52M, and now plans to produce 80 sets of M, N fashions with these two fabrics. It is known that making a set of M fashions needs 0.6M and 0.9M of fabric A and fabric B, which can be profitable. 45 yuan, to make a set of N pieces of fashion, you need fabric A 1. 1m and fabric 0.4M.

The price of Type A refrigerator in a shopping mall is 2 190 yuan. Recently, I bought a batch of B-type refrigerators in shopping malls, which are 65,438+00% higher than A-type refrigerators, but the daily power consumption is lower than A-type refrigerators. In order to reduce inventory, the mall decided to sell Type A refrigerators at a reduced price. It is known that the purchase price of type A refrigerator is 1700 yuan, and in order to ensure the profit rate of shopping malls is not lower than

6. A real estate development company plans to build 80 housing units A and B, and the funds raised by the company are not less than 20.9 million yuan, but not more than 20.96 million yuan, all of which are used for building houses. The construction costs and selling prices of these two units are as follows:

Unit 10,000 yuan/set

A b

Cost 25 28

Price 30 34

7 "Lihai" communication equipment shopping mall plans to buy new mobile phones from manufacturers at a price of 60,000 yuan to meet the market demand. It is known that the manufacturer produces three different models of mobile phones, and the ex-factory price is RMB 0.8 million per model A, RMB 0.2 million per model B and RMB 0.2 million per model C..

(1) If the mall buys 40 mobile phones of two different models at the same time and just runs out of 60,000 yuan, please help the mall figure out how to buy them;

(2) If the mall buys ***40 mobile phones of three different models at the same time, and 60,000 yuan is just used up, the number of mobile phones of model B is required to be no less than 6 and no more than 8. Please find out the number of mobile phones of various models in the mall.

eight

A batch of goods is transported by a number of cars with a deadweight of 8 tons. If each car only carries 5 tons, there is still 10 tons of goods left. If each car is full of 8 tons, the last car will be empty and dissatisfied. How many cars are there?

9. (Ningbo Senior High School Entrance Examination in 2002) In order to make effective use of power resources, Ningbo Electric Power Bureau has conducted a pilot project of residential peak and valley electricity consumption since June 65438+ 10, 2002, with electricity consumption of 0.56 yuan per kilowatt-hour from 8:00 to 22: 00 every day ("peak electricity" price), and from 22: 00 to 8: 00 the next day.

10. (Quanzhou City, Fujian Province, 2003) A class organized mountaineering activities on weekends. Students were divided into two groups, A and B, and walked from the foot of the mountain to the top of the mountain at the same time along a road. Let's assume that the time ratio of two groups of people traveling the same distance is 2: 3.

(1) Write the speed ratio of group A and group B directly;

(2) When Group A reaches the top of the mountain, Group B heads for mountainside A, and the distance from the top of the mountain is still 1.2km, so how far is the distance from the foot of the mountain to the top of the mountain?

(3) On the basis of the content mentioned in the question (except the last question), group B is set to continue climbing from place A, and group A will take a short rest after reaching the top of the mountain, then go down the mountain by the original road and meet group B halfway up the mountain. Please ask the corresponding questions according to the above situation first, and then give an answer (requirements: ① No other conditions may be attached to the questions; (2) The problem must be solved by using all the known conditions provided by the above scenario).

11(Huanggang City, Hubei Province, 2000) It is known that Yamei Garment Factory currently has 70-meter fabric A and 52-meter fabric B, and now plans to produce 80 sets of M and N fashions with these two fabrics. It is known that making a set of M fashion needs 0.6 m fabric A and 0.9 m fabric B, which can make a profit in 45 yuan; To make an N-style fashion, you need 1. 1.0 m A fabric and 0.4 m B fabric, and you can make a profit, 50 yuan. If the number of sets of N-fashion is X, the total profit of producing these two kinds of fashion with these fabrics is Y yuan.

(1) Find the functional relationship between Y (element) and X (set), and find the range of independent variable X;

(2) In the production of this batch of fashions, Yamei Garment Factory has the largest profit when the number of N-type fashions is set. What is the maximum profit?

12 The starting price of taxis in a city is 10 yuan (that is, the taxi fare within 5km is 10 yuan). After reaching or exceeding 5km, increase 1. 2 yuan for every driving 1 km (if it is less than 1 km, it shall be counted as1km).

13: When blasting, the burning speed of fuse is 0.9cm per second. Whoever ignites the fuse needs to run away from 120m to be safe. If he runs at a speed of 6m per second, how long should the fuse be?

In addition, I will send you a summary of inequality application problems.