2, the fifth grade cleaning, originally planned to send students to the playground to weed, the rest of the students to sweep the floor, actual labor, and two students to participate in weeding, so the number of weeding is the number of sweeping the floor, originally planned to send several students to weed.
There are 1 12 books on two floors. If the second floor is moved to the first floor, the number of books on the two floors is equal. How many books are there on the second floor?
4. The ratio of male students to female students in bright primary school is 7:5, and then it changed to 12 female students. At this time, the ratio of boys to girls is 9:7. How many girls are there in school now?
A 5.6-meter-long bamboo pole is inserted in the pool to expose the water surface, and the rest is inserted in the mud. How deep is this swimming pool?
6. The agricultural company transferred the first team to the second team. At this time, the people in the second team happened to belong to the first team. The second team is known to have 22 people. How many people are there in the first team?
Xiao Ming originally planned to finish reading a book in 20 days, but he finished reading 40% of the whole book in 5 days. At this rate, he can finish reading it a few days in advance.
8. There is a pile of fruits, among which apples account for 45%. After adding 16 kg pear, apples account for 25%. How many kilograms of apples are there in this pile of fruit?
9. Make a cube into the largest cylinder. Given that the volume of a cylinder is 392.5 cubic centimeters, how many cubic centimeters is the volume of a cube?
10, the experimental school sent 60 contestants to participate in the "Children's ok Competition", among which female contestants accounted for the majority. In the official competition, several female players were absent for some reason, so that the number of female players became the total number of participants. How many girls have officially entered the competition?
165438+
12, the kindergarten bought some books. Science books are picture books and story books, and picture books are science books and story books. There are 15 story books. How many science and technology books and picture books are there?
13, water conservancy project, completed by two teams in 30 days. If the two teams 12 days are repaired, the rest will be completed by team b alone, 24 days. How many days does it take for Party A and Party B to do this project alone?
14, there are two classes A and B in the fourth grade of workers and peasants primary school. The number of class A is the number of class B. If three people are transferred from class B to class A, the ratio of class A to class B is 4:5. How many people are there in each class?
15, water conservancy project, 8 days for Party A and 4 days for Party B.. Party A and Party B cooperate, and Party A takes a rest due to illness 1 day. When finishing the task, Party B worked for several days.
16. It takes 10 hour for the bus to travel from place A to place B, and 15 hour for the truck to travel from place B to place A, and both cars travel in opposite directions at the same time. When they met, the bus traveled 80 kilometers more than the truck. Find out the distance between Party A and Party B..
17, a class has a meeting, and the number of people who ask for leave is the number of people present. In this way, the number of people on leave is the number of people present. How many students are there in this class?
18, it takes 8 hours for the master to complete a batch of parts by himself. It is known that the work efficiency ratio of master and apprentice is 4:3, and how long it takes for apprentice to complete it alone (proportional solution).
19, self-employed people shipped 385kg tomatoes and eggplant. After the tomatoes and eggplant are sold out, the remaining two dishes are of equal quality. How many kilograms of tomatoes and eggplant were shipped?
20. The weight ratio of two bags of rice is 3: 10. If Party B gives Party A 20kg, this is the weight ratio of two bags of rice, 7:6. Find out how many kilograms each of the original two bags of rice weighed.
2 1, A and B are in the pool. The sum of the lengths of the two sticks is 190cm. Bonzi A is out of water, and Bonzi B doesn't sleep. How many centimeters is the water depth?
22. Two cars, A and B, travel in opposite directions from east and west at the same time. It is known that the speed ratio of Party A and Party B is 2:3. It takes Party A five hours to complete the journey, so that the two cars can meet each other a few hours after departure.
23. The production of a forklift has been reduced by 4.5 hours from the original 7 hours, and the original daily production is 65,438+040 units. How many units are produced every day now (using the positive-negative ratio scheme)?
24. It takes 40 days for Party A to do a job alone, and 60 days for Party B to do it alone. Now working together, Party A will take a few days off due to illness. After 27 days, Party A will have a few days off.
25. When reading a book, the ratio of read to unread is 3:4. If you read 50 more pages, you will have read twice as much as you have not read. How many pages are there in this book?
26. There are two meshing gears, the big gear with 48 teeth and the small gear with 32 teeth. If the big gear rotates 100 rpm, how many revolutions does the pinion rotate in 20 seconds (proportional solution).
27. It takes six hours for the bus to go from A to B, and four hours for the truck to go from B to A. Now, the two cars start from A and B at the same time, heading in opposite directions. Therefore, they meet at a distance of18km. How many kilometers did the truck travel when they met?
28. The raw material weight ratio of warehouse A and warehouse B is 7:5. If warehouse A gives warehouse B 26 tons, then warehouse A belongs to warehouse B, then how many tons of goods did warehouse A originally have?
29. After cutting the circular iron sheet with a radius of 30 cm, roll the rest into a lampshade. What is the radius of the circle at the bottom of the lampshade?
30. After dividing the bottom of a cylinder with a height of 4 cm into several sectors, cut the cylinder and put it together to form an approximate cuboid as high as its bottom. The surface area of a cuboid is increased by120cm2 compared with that of a cylinder. What is the original volume of this cylinder?
3 1, there is a pile of fruits, and apples account for 45%. After adding 16 kg pear, apples account for 25%. How many kilograms of apples are there in this pile of fruit?
32. The fruit warehouse delivered 400 kilograms of fruit with 90% water content. After a week's measurement, it was found that the water content was reduced to 80%. What is the total weight of this batch of fruit now?
33. Two cars, A and B, start from A and B at the same time and drive in opposite directions. A travels 80 kilometers per hour, and B travels 65,438+00% of the whole journey per hour. When B drives all the way, how many kilometers does Party A drive all the way to B, A and B?
34. The weights of these two piles of coal are equal. 2.5 tons were taken out of pile A and put into pile B, and the weight ratio of the two piles of coal was 3:5. How many tons of raw coal were found in pile A?
35. The school bought a new batch of science and technology books and story books, accounting for the total, and later bought 80 science and technology books. At this time, science and technology books account for the total. How many books did the school originally purchase?
36. It takes 4 hours for A to walk from East Town to West Town and 6 hours for B. If A starts from East Town and B starts from West Town at the same time, they will walk in opposite directions. When they meet, A will walk 12 kilometers more than B, thus finding out the distance between the two towns.
37. A project will be completed after 8 days of cooperation between Party A and Party B. After Party A goes it alone 12 days, Team B will go it alone for 6 days. At this time, the whole project was completed. How many days does it take for Party A to do this project alone?
38. The ratio of the school art interest group to the music interest group is 5:4, and seven people joined the art interest group halfway. At this time, the ratio of the two groups is 8:5. How many people are in each of the two interest groups?
39. It takes 5 minutes for a master to make a part and 9 minutes for an apprentice to make a part. If mentoring cooperates 168, ask how much each earns.
40. Two teams will complete a project in 65,438+02 days. First, Team A will do it alone for 6 days, and the rest will be done by Team B for 2 1 day. If all teams are completed by team B, how many days will it take?
4 1, a project is completed in 20 days by Party A and 30 days by Party B. After 30 days, Party B asks for leave because of something, and it takes 14 days from the start to the completion, and Party B asks for leave for a few days.
42. It takes 1O hours for the bus to go from place A to place B, and 15h for the truck to go from place B to place A, and both cars are driving in opposite directions at the same time. When they met, the bus traveled 80 kilometers more than the truck. Find the distance between a and b.
43. There are 27O parts. Party A will finish it in 5 days and Party B will finish it in 4 days. Divide these parts among two people. How much should everyone get if they want to finish it at the same time?
44. The production time of each farm tool in the farm tool factory has been reduced from seven minutes to four or five minutes. L4O kinds of farm tools were produced every day. How many farm tools are produced every day now (by positive-negative ratio solution)?
45. Pave the 16OO block needed by the first workshop with square bricks with a side length of 4 decimeters; Now it is paved with square bricks with a side length of 5 minutes. How many pieces (proportion) are needed?
46. There are two meshing gears, the big gear with 96 teeth and the small gear with 16 teeth; If the big gear rotates 1OO revolutions per minute, how many revolutions (proportion) does the pinion rotate every 40 seconds?
47. There is a pool of water. When the water turns into ice, its volume increases by L/11; When ice melts into water, its volume is reduced by a fraction.
48. Take a box of 168 light bulbs first, then take the remaining 2/3, leaving l/7 of the total. How many light bulbs are there in this box?
49. In the sixth grade, 1.5 students participated in the extracurricular activity group, and then two students participated in the extracurricular activity group. The actual number of participants is 1/3 of the rest. How many students joined the extracurricular activity group?
50. The original ratio of the two training teams was 4:3, and 48 people were transferred from Team A to Team B. Now the ratio of the two teams is 2:3. How many people are there in Team A?
5 1, the number of machines produced by a factory in the first, second and third quarters is 75% of the whole year, and that in the third and fourth quarters is 45% of the whole year. It is known that 200 units will be produced in the third quarter. How many machines does this factory produce throughout the year?
52. A job is divided equally between Party A and Party B, and it takes Party A 5 hours and Party B 8 hours to complete it. How many hours can two people do together?
53. Warehouse A and Warehouse B have * * * stored grain1680 tons, 3/4 of which are shipped from Warehouse A and 2/3 from Warehouse B, and the surplus grain of the two warehouses is equal. How many tons of raw grain are there in warehouses A and B?
54. The average score of a class in an exam is 7O, 3/4 passed, and the average score is 8O. Seek the average score of those who fail.
55. When sailing downstream, the speed of the ship is 1O kilometers per hour, and when sailing upstream, the speed of the ship is 6 kilometers per hour. Find the average speed of the ship going back and forth.
56, A, B, C is 52, A, C is 55, B, C is 57. What's a, b and c?
57, the clock strikes 4 times at 4 o'clock and knocks out in 6 seconds; Then knock 12 at 2 o'clock, and knock it out in a few seconds (tree planting problem)
58. If a commodity is sold at a fixed price, the profit is 96 yuan. If it is sold at 80% of the pricing, the loss will be 832 yuan. What is the purchase price of goods (profit problem)?
59, the sugar water with the concentration of lO% and the weight of 80g is added with a few grams of sugar, which becomes the sugar water with the concentration of 2O% (concentration problem).
60. Put a round steel with a radius of 5 cm into a cylindrical water storage bucket. If you put it all in a bucket, the water in the bucket will rise by 9 cm. If the round steel in the water is 8 cm higher than the water surface, the water in the bucket will drop by 4 cm, and the volume of the round steel will be calculated.
6 1, divide the bottom of the cylinder into 4O parts, and then cut it into approximate cuboids. It is known that the circumference of the bottom of a cuboid is 16.56cm and the height is 8cm. Find the volume of a cylinder (by hand).
62. Passenger ships and cargo ships leave from Port A and Port B at the same time, and passenger ships sail from Port A to Port B at a speed of 30 kilometers per hour. The cargo ship sailed from Port B to Port A 1/36 hours. When the passenger ship is away from Port A180 km, the cargo ship is just away from Port B120 km. How many kilometers are the two ports apart?
63. Shengli Primary School has three extracurricular groups: Science and Technology Group 1O students, accounting for 20% of the total number of the three groups. The ratio of art group to sports group is 3:2. How many people are there in the sports group?
64. At the end of the autumn harvest, Uncle Zhang harvested a pile of rice. He intends to sell the rest except leaving enough rations. He knew the market situation in advance: rice per kilogram 1. In 50 yuan, the rice is 2.20 yuan per kilogram, and the rice yield is 70%. If rice is processed into rice, bran money can offset the processing cost. Please help me sum it up. Uncle Zhang is very economical in selling rice.
65. In the construction of Jingjiang Tongda Project, Xieqiao Town originally planned to lay a cement road with a length of 5,000m, a width of 12m and a thickness of 25cm from the Xieqiao Bridge in two months. 40% of the roads were paved in the first 25 days. According to this progress, can this expressway be completed as scheduled (with different methods to solve the problem, plus points)?
66. How many yuan does Xiao Ming have? The first time I spent 2/5, I got 24 yuan. After spending 1/3 of all the money at this time for the second time, 72 yuan was left. How much did he spend for the first time (reverse calculation)?
67. There are 135 students in Class A and Class B, and the sum of Class A 4/7 and Class B 4/5 is 92. How many students are there in Class A and Class B (hypothetical method)?
68. Operation problem: There are five cakes of the same size, which should be distributed to six Xiaoming friends equally, so that each child can get two cakes, and everyone can take them in the same way. How to draw a schematic diagram?
69. Wang Hong is 9 years old and Wujiang 19 years old. A few years ago, Wujiang was three times as old as Wang Hong.
For a project, it takes 15 days for Team A to do it alone, and 12 days for Team B to do it alone. After the two teams finish together for a few days, team B needs three days to finish the rest of the work. How many days did Team A and Team B work together?
70. Group A and Group B produce a batch of parts at the same time. It takes 5 days for group A to do it alone, and 3 days for group B to do it alone. These two groups cooperate to produce 1600 parts every day. How many parts are there in this batch?
7 1, with a cuboid glass jar filled with water and a cylindrical steel ingot with a bottom area of 3. 14 square decimeter. When the ingot is taken out of the glass jar, the water level in the jar drops by 0.5 decimeter. It is known that the bottom area in a rectangular glass jar is 28.26 square decimeters. Find the length of this cylindrical ingot.
72. Two cars, A and B, leave from A and B respectively at the same time. After driving for 4 hours, the two cars have met, 75 kilometers apart. It is known that two cars can travel 7/24 of the whole journey every hour. How many kilometers is it between A and B?
73. Taxis in a city are charged as follows:
Li Cheng
Charge/yuan
Less than 5 kilometers
10.00
More than 5 km, each increase of 1 km.
1.20
(1) If the taxi mileage is15km, () yuan shall be charged;
② Now that we have 30 yuan money, the maximum mileage we can take a taxi is () kilometers.
74. The length, width and height of a rectangle are 3,2, 1 cm, respectively. A bug starts from a vertex and crawls along the edge. If the repeated route is not required, the longest path taken by the bug when it returns to the vertex at the beginning is () cm.
75. The original cement weight ratio of the two construction teams was 4:3. When Team A gave Team B 54 tons of cement, the cement weight ratio of Team A and Team B was 3:4. How many tons of cement does Team A have?
76. The surface area of a cylinder with a diameter of 10 cm is increased by 200 square centimeters after being cut longitudinally along the diameter. What is the original volume of this cylinder?
77. The cylindrical container A is empty, and the water depth in the rectangular container B is 6.28 cm. It is necessary to pour all the water in container B into container A. What is the water depth at this time?