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The first volume of junior one mathematics expands the question bank
1、- 15+6÷(-3)× 1/2

2、( 1/4- 1/2+ 1/6)×24

3、|-5/ 14|×(-3/7)2÷3/ 14

4、2/3+(- 1/5)- 1+ 1/3

5、23+(-73)

6、(-84)+(-49)

7、7+(-2.04)

8、4.23+(-7.57)

9、(-7/3)+(-7/6)

10、- 1+2-3+4-5+6-7;

1 1、- 1+8-7 )23+(-73)

12、(-84)+(-49)

13、7+(-2.04)

14、4.23+(-7.57)

15、(-7/3)+(-7/6)

16、9/4+(-3/2)

17、3.75+(2.25)+5/4

18、-3.75+(+5/4)+(- 1.5)

19、(- 17/4)+(- 10/3)+(+ 13/3)+( 1 1/3)

20、(- 1.8)+(+0.2)+(- 1.7)+(0. 1)+(+ 1.8)+(+ 1.4)

2 1.5/7 × 3/25 + 3/7

22.3/ 14 ×× 2/3 + 1/6

23. 1/5 × 2/3 + 5/6

24.9/22 + 1/ 1 1 ÷ 1/2

25.5/3 × 1 1/5 + 4/3

26.45 × 2/3 + 1/3 × 15

27.7/ 19 + 12/ 19 × 5/6

28. 1/4 + 3/4 ÷ 2/3

29.8/7 × 2 1/ 16 + 1/2

30. 10 1 × 1/5 – 1/5 × 2 1

3 1.50+ 160÷40 (58+370)÷(64-45)

32. 120- 144÷ 18+35

33.347+45×2-4 160÷52

34(58+37)÷(64-9×5)

35.95÷(64-45)

36. 178- 145÷5×6+42 420+580-64×2 1÷28

37.8 12-700÷(9+3 1× 1 1) ( 136+64)×(65-345÷23)

38.85+ 14×( 14+208÷26)

39.(284+ 16)×(5 12-8208÷ 18)

40. 120-36×4÷ 18+35

4 1.(58+37)÷(64-9×5)

42.(6.8-6.8×0.55)÷8.5

43.0. 12× 4.8÷0. 12×4.8

44.(3.2× 1.5+2.5)÷ 1.6

45.6- 1.6÷ 0.5

46.7.2÷0.8- 1.2×5

47.6.5×(4.8- 1.2×4)

48. 10. 15- 10.75×0.4-5.7

49.5.8×(3.87-0. 13)+4.2×3.74

50.32.52-(6+9.728÷3.2)×2.5

5 1.-5+58+ 13+90+78-(-56)+50

52.-7*2-57/(3

53.(-7)*2/( 1/3)+79/(3+6/4)

54. 123+456+789+98/(-4)

55.369/33-(-54-3 1/ 15.5)

56.39+{3x[42/2x(3x8)]}

57.9x8x7/5x(4+6)

58. 1 1x 22/(4+ 12/2)

59.94+(-60)/ 10

60.3.2×( 1.5+2.5)÷ 1.6

6 1.3/7 × 49/9 - 4/3

62.8/9 × 15/36 + 1/27

63. 12× 5/6 – 2/9 ×3

64.8× 5/4 + 1/4

65.6÷ 3/8 – 3/8 ÷6

66.4/7 × 5/9 + 3/7 × 5/9

67.5/2 -( 3/2 + 4/5 )

68.7/8 + ( 1/8 + 1/9 )

69.9 × 5/6 + 5/6

70.3/4 × 8/9 - 1/3

A factory applied for two kinds of loans from ICBC, namely, * * * 200,000 yuan with annual interest of 27,000 yuan. The annual interest rate of loan A is 12%, and that of loan B is 14%. What are the amounts of loans A and B respectively?

2. A vendor sold two clothes at the price of 135 yuan. According to the cost calculation, the first company earned 25% and the second company lost 25%. So how much did the supplier earn (or lose) in this business?

3. Company A borrows120,000 yuan from the bank, and the annual interest rate is 10% (excluding compound interest). Use this loan to buy a set of imported equipment to produce a commodity, and the production cost of each box of commodities is 100 yuan. The sales price is 150 yuan, and the comprehensive tax rate is 10% of the sales price.

4. Someone saved 100 yuan. At that time, the annual interest rate was 7.47% and the three-year interest rate was 8.28% (excluding compound interest). A deposit method: first deposit for one year, then deposit the principal and interest for another year after maturity, and then deposit the principal and interest for another year after maturity; The second deposit method: three years; Which deposit method has higher income? How much more?

5. There are 72 students from two classes who go to the construction site to take part in the voluntary labor of digging and moving earth. If each person digs 3 cubic meters or transports 5 cubic meters of soil every day on average, how should the number of people digging and transporting soil be distributed so that the excavated soil can be transported away in time?

6. There are 42 workers in a workshop, and each person can produce 2 bolts or 3 nuts per minute. How many workers should be assigned to produce bolts and nuts in order to make them just match (one bolt with two nuts)?

7. The number of workers in three workshops of a factory is 26, 39 and 65 respectively, and 40 contract workers are now recruited. How should it be distributed so that the proportion of workers in each workshop is the same as before?

8. 20 kg of salt water with salt content 15%. How many kilograms of salt does it take to increase the salt content to 20%?

9. There is 60 grams of 5% salt water. How many grams of water should be added to get the salt with the mass fraction of 10%?

10.40 kg of brine with salt content of 12.5%, how many kilograms of water can be evaporated to make brine with salt content of 20%?

1 1. How many grams does it take to get 1000% brine with 25% salt content?

12. Add 20g of salt into the brine with a salt content of 20% to obtain the brine with a salt content of 25%. How many grams of raw salt water?

13. How many kilograms of 98% pure sulfuric acid and water are needed to prepare 1000% pure sulfuric acid 1000 kg, compared with 85 kg of 60% pure sulfuric acid?

14. A worker originally planned to process a batch of parts in a limited time. If he processes 10 parts per hour, he can overfulfil 3 parts. If 1 1 parts are processed every hour, it can be finished at 1 hour in advance. How many parts are there in this batch? How long will it take to finish as planned?

15, Party A and Party B jointly produced a batch of parts, which took 20 days to complete the task. And Party B took five days off midway, knowing that Party A has made three more parts than Party B in one day, then the parts made by Party B are exactly half of those made by Party A. Find the total number of these parts.

16, it takes 12 days for Xiao Ming to make a batch of parts. Two days later, Xiaoming adopted advanced technology, and his work efficiency doubled. How long did it take Xiao Ming to finish this task?

It takes 17, Party A, Party B, Party C 10 days, 12 days and 15 days to complete the same job alone.

(1) If three people cooperate, * * * How many days will it take to complete this task?

(2) If Party B does it for 3 days first, and then Party A and Party C join in at the same time, how many days will it take to complete the work?

(3) A did it first, then B and C added * * *, and it took 7 days before and after. A How many days did you do it for the first time?

18. There are three water pipes A, B and C in a pool. A is the water inlet pipe, and B and C are the drainage pipes. A needs to fill a pool of water at 6 o'clock when driving alone, and B needs to drink it at 8 o'clock when driving alone. In an empty pool, first open water pipe A at 3 o'clock, and then open water pipes B and C at the same time. After 2: 24, all the water in the pool was drained. Request to open pipe C separately, complete.

19, A and B practice short distance running, A is 7 meters per second, and B is 6.5 meters per second.

(1) If A lets B run 5 meters first, how many seconds can A catch up with B?

② If A lets B run first 1 sec, how many seconds can A catch up with B?

A correspondent needs to deliver the letter to a certain place within the specified time. If he rides his bike every hour15km, he will arrive 24 minutes earlier. If your speed is12km, you will be 30 minutes late. When is the scheduled time? How far is his journey to a place?

2 1, Party A and Party B walk from A and B of an expressway at 8: 00 a.m., the distance between them is shortened to 10 km at 8:30 a.m., and increased to 44 km at 10: 20 a.m., so as to find the distance between A and B. 。

22. The two trains, A and B, are 200 meters and 280 meters long, respectively, and run in opposite directions on parallel tracks. It is known that it takes 18 seconds for two cars to meet in front and then separate, and the speed ratio of A to B is 5: 3. Find the speed of two cars.

23. It is known that the length of a railway bridge is 1000m, and a train passes through the bridge. It takes 1 minute for the train to cross the bridge completely from the beginning, and the whole train stays on the bridge completely for 40 seconds. Find the length and speed of the train.

24. Party A and Party B set out from two places, which are 18km apart, and walked towards each other. They met at 1. If Party A leaves before Party B, they will meet at 1 after Party B leaves. Seek the speed of both parties.

25. Someone rides a bicycle for one hour on the level road 12km, 8km on the uphill road and 1 hour on the downhill road 15km. It is understood that the horizontal road of a section of road is 28 kilometers long, and it took someone five hours and 4.39 minutes to come back by bike. How many kilometers is the uphill and downhill in this section?

26. For a two-digit number, the tenth digit is twice as large as the single digit. If the positions of ten digits and single digits are reversed, the number obtained is 36 less than the original number, and the original two digits are found.

26. A factory should complete the assembly task of 18 tractors within 5 days. Workshop A can assemble 2 tractors every day, and Workshop B can assemble 3 tractors every day. How to allocate the assembly tasks of two workshops so that the working days of both workshops are all day?

27. Hongqi Machinery Factory produces two kinds of machines, A and B. Each machine costs 40,000 yuan, and B costs 50,000 yuan.

(1) In order to make the sales amount reach 1.2 million yuan, how many machines should be arranged to be produced if two kinds of machines are to be produced?

(2) If the market demand for Type A machines does not exceed 20, and the demand for Type B machines does not exceed 15, how should the factory arrange the production plan to ensure the sales of 1.2 million yuan?

28. For a three-digit number, the sum of the hundredth digit and the last two digits is 58. If the number of the hundredth digit is shifted to the number of one digit, and the original number of the tenth digit and the number of one digit are successively raised to the number of the hundredth digit and the number of one digit, the new three digits are 306 larger than the original number. Find the original three digits.

29. Three digits, in which the decimal is less than 2, and the sum of hundred digits and single digits is 14. If the hundred digits and the single digits are exchanged, the new number is 396 larger than the original number, and the original three digits are found.

30. A warehouse has 20 A-class goods and 29 B-class goods to be delivered to department stores. Each truck can transport 5 Class A goods or 4 Class A goods and 3 Class B goods at a time. Each van can transport 10 pieces of Class B goods or 2 pieces of Class A goods and 5 pieces of Class B goods at a time. Long-distance charge for large trucks is 300 yuan, and long-distance charge for small trucks is 180 yuan.

(1) How many times does it take for a big truck to transport Class A goods and a small truck to transport Class B goods?

(2) How many times does it take for a big truck and a small truck to ship two kinds of goods at the same time?

(3) (1), (2) Which of the two transportation schemes saves the transportation cost, and what is the transportation cost with less?

3 1. A factory produces two different types of machines, A and B. According to the original production plan, the production cost of A machine is 30,000 yuan each, and the production cost of B machine is 20,000 yuan each. The total cost of completing all the plans is 690,000 yuan. Further accounting shows that if the output of A-machine increases by 5 and that of B-machine decreases by 5 in the original plan, the cost of A-machine will be reduced to each 2 yuan.

32. The original planned profit of an enterprise this year is 320,000 yuan more than the management expenses. The reward method is: the total bonus = the actual profit exceeds 40% of the planned amount+the management fee expenditure is lower than 60% of the planned amount. It is estimated that if the actual profit reaches 600,000 yuan, the management expenses will be reduced to 6.5438+0.2 million yuan, and the year-end bonus of employees will total 70,000 yuan. Now the total year-end bonus of employees will reach 90 thousand yuan, and the management fee expenditure will be controlled.

33, planting trees on both sides of the road, every 3 meters, leaving 3 trees; There is a tree every 2.5 meters, and 77 trees are gone, so we need a long way.

34. A toy company manufactures toy guards and toy cavalry on a machine with working hours of 10 every day. It takes 8 seconds and 8 grams of metal to be a toy guard, 6 seconds 16 grams of metal to be a toy cavalry, and the daily supply of metal materials is 64 kilograms. The profit of being a toy guard is 0.05 yuan, and the profit of being a toy cavalry is 0.06 yuan. How many toys were made? What is the daily profit of this production arrangement?

35. The distance between A and B is 10 km. A, B and C walk from A to B. The walking speed of A and B is 4 kilometers per hour, and the speed of C riding a motorcycle is 40 kilometers per hour. When starting, C rides a motorcycle with A first. After C gives A a ride, A gets off and walks, and C walks back to meet B.. As a result, three people arrived at B at the same time.

36. Party A, Party B and Party C leave from Party A to Party B at the same time. C walked first. A takes B somewhere on the way by bike. B got off and walked to B. A rode back to meet C and took C to B. As a result, three people arrived at B at the same time. It is known that walking is 4 kilometers per hour, cycling is 12 kilometers per hour, and the distance between A and B is 90 kilometers. ask

B how many kilometers did you walk?

37. Li Ying got 72 points in the first math exam and 86 points in the second exam. How many points does she need in the third exam to make the average score of the three exams not less than 80?

38. In an exam, * * * gave 25 questions, and each question gave 4 answers, of which only one answer was correct. If each question was correct, 4 points were given, and 2 points were deducted if it was not wrong. If a student scores at least 60 points, how many questions does he answer correctly at least?

Hey, hey, that's all I have. If there is no answer, you will get extra points.