2. There are three meadows of 5, 15 and 24 acres respectively. The grass is equally thick and grows equally fast. The first plot of grass is good for 10 cows for 30 days, the second plot is good for 28 cows for 45 days, ask how many cows can be fed in the third plot for 80 days?
3. A project, contracted by teams A and B, can be completed in 2.4 days for $1800; by teams B and C, it can be completed in 3+3/4 days for $1500; by teams A and C, it can be completed in 2+6/7 days for $1600. Which team is chosen to contract alone at the least cost with the guarantee of completion in one week?
4. A cylindrical container with a rectangular iron block. Now turn on the faucet and fill the container with water. 3 minutes the water is just below the top surface of the rectangular. The water fills the container in 18 minutes. The height of the container is known to be 50 centimeters, the height of the rectangle is 20 centimeters, find the ratio of the area of the bottom of the rectangle and the area of the bottom of the container.
5. A, B two bosses were purchased at the same price of a fashion, B purchased the number of sets than A more than 1/5, and then A, B, respectively, according to get 80% and 50% of the profit pricing to sell. Both are all sold out, A is still more than B to obtain a portion of the profit, this part of the profit and just enough for him to purchase this fashion 10 sets, A originally purchased this fashion how many sets?
6. A, B two water pipes, respectively, at the same time to A, B two pools of the same size water injection, in the same time A, B two tubes of water injection ratio is 7: 5. After 2 +1/3 hours, A, B two pools of water injected into the sum of exactly one pool. At this time, the A tube injection rate increased by 25%, the B tube injection rate unchanged, then, when the A tube is filled with A pool, the B tube and then after how many hours to fill the B pool?
7. Xiaoming morning from home to school on foot, walk half of the distance, his father found Xiaoming's math book lost in the house, and then rode to Xiaoming to send the book, catching up, Xiaoming still have 3/10 of the distance has not been completed, Xiaoming then got into the car of his father, his father sent to the school, so that Xiaoming 5 minutes earlier than the solo walk to the school. How much time does it take for Ming to walk all the way from home to school?
8. Two cars A and B are traveling from A to C via B. The distance between A and B is equal to the distance between B and C. The speed of car B is equal to the speed of car A. The speed of car B is equal to the speed of car A. The speed of car B is equal to the speed of car A. The speed of car B is 80% of car A's speed. Car B starts 11 minutes before car A, but stops at B for 7 minutes, while car A keeps going to C. Car B starts 4 minutes later than car A, but stops at B for 7 minutes. At the end, car B arrives at C 4 minutes later than car A. Then car A overtakes car B a few minutes after car B leaves.
9. Two cars, car A and car B, are sweeping the highway between the East and West Side. It takes 10 hours for car A to sweep alone, and 15 hours for car B to sweep alone. The two cars drive in opposite directions from the east and west at the same time, and when they meet, car A sweeps 12 kilometers more than car B. How many kilometers are the east and west cities apart?
10. Today there are 4 containers weighing 3 tons, the weight of 2.5 tons of containers 5, the weight of 1.5 tons of containers 14, the weight of 1 tons of containers 7. What is the minimum number of cars with a load capacity of 4.5 tons that can be used to carry all the containers at once?
Primary school math application problems comprehensive training (02)
11. Master and apprentice two people **** with the processing of 170 parts, the master processed the number of parts 1/3 than the apprentice processed the number of parts 1/4 more than 10, so the apprentice a **** processed a few parts?
12. A big car and a small car are traveling from A to B. The speed of the big car is faster than the speed of the small car. The speed of the car is 80% of the speed of the car. It is known that the bus leaves 17 minutes before the minibus, but stops at the midpoint of the two places for 5 minutes before continuing to B. The minibus does not stop after departure, but goes directly to B, and the minibus finally arrives at B 4 minutes earlier than the bus. It is also known that the limousine departed from place A at 10:00 a.m.. So when did the car catch up with the bus in the morning.
13. A book manuscript takes A 14 hours to type and B 20 hours to type. If A types it for 1 hour, then B takes over from A for 1 hour, then A takes over from B for 1 hour ....... both of them work in this way alternately. Then when typing this manuscript, A and B **** with how many hours?
14. yellow balloons 2 yuan 3, flower balloons 3 yuan 2, the school *** bought 32 balloons, including flower balloons than yellow balloons 4 less, the school to buy which balloons with more money?
15. A sailboat speed is 60 m / min, the boat in the current speed of 20 m / min of the river, from the upstream of a port to the downstream of a place, and then return to the original place, *** with 3 hours and 30 minutes, this boat from the upstream of the port to the downstream of a place *** walked how many meters?
16. Granary A is loaded with 43 tons of flour, granary B is loaded with 37 tons of flour, if the flour of granary B is loaded into the granary A, then after the granary A is full, the flour left in the granary B accounted for the capacity of the granary B 1/2; if the flour of the granary A is loaded into the granary B, then after the granary B is full, the flour left in the granary A accounted for the capacity of the granary A 1/3, how much flour can be loaded in each granary? How many tons of flour can each bin hold?
17. Number A divided by number B, number B divided by number C, the quotient is equal, the remainder is 2, A, B and the sum of the two numbers is 478.
18. A car is traveling from A to B. If the speed of the car is reduced by 10%, it will be able to drive from A to B. If the speed of the car is reduced by 10%, then it will arrive 1 hour later than the scheduled time. If the car travels at the original speed of 180 kilometers and then increases the speed by 20%, then it will arrive 1 hour earlier than the scheduled time. What is the distance in kilometers between A and B?
19. A school to participate in the military training team performance competition, the organization of a square team. If each class 60 people, this square at least 4 classes of students to participate, if each class 70 people, this square at least 3 classes of students to participate. Then how many people should form this square?
20. A, B, C three lathes processing square and round two kinds of parts, known as the A lathe every processing 3 parts in 2 is round; B lathe every processing 4 parts in 3 is round; C lathe every processing 5 parts in 4 is round. This day the three lathes *** processed 58 round parts, and the number of square parts processed in the ratio of 4:3:3, then this day the three lathes *** processing parts how many?
Primary school math application problems comprehensive training (03)
21. circle metal line 30 meters long, intercept the length of A metal line 3, the length of B metal line 5, the rest of the metal line, if you then intercept 2 length of B metal line is still short of 0.4 meters, if you then intercept 2 lengths of A metal line is also short of 2 meters, the length of A is equal to a few meters?
22. A company to deliver to the site A, B two kinds of building materials. A building materials weighing 700 kg each, *** there are 120 pieces, B building materials weighing 900 kg each, *** there are 80 pieces, a car is known to carry a maximum of 4 tons each time, then five identical cars at the same time, at least a few times?
23. The distance from Wang Li's home to the school is 1/4 longer than the distance to the stadium, one day after Wang Li watched a ball game in the stadium with 17 minutes of time to walk to his home, after a short break, he used 25 minutes to walk to the school, its speed is slower than from the stadium back to the 15 meters per minute, the distance from Wang Li's home to the school, what is the distance in meters?
24. master and apprentice two people cooperate to complete a project, due to good cooperation, the master's efficiency than alone to do 1/10, the apprentice's efficiency than alone to do 1/5. two people work together for 6 days, the completion of all the works of the 2/5, and then the apprentice alone to do 6 days, then the project is still 13/30 is not completed, if the project by the master one person to do, how many days? Finish?
25. five classes of sixth grade students **** planted 100 trees. It is known that the number of trees planted by each class is different, and in descending order of the number of trees planted is exactly one, two, three, four and five. It is also known that the number of trees planted in class 1 is the sum of the number of trees planted in classes 2 and 3, and the number of trees planted in class 2 is the sum of the number of trees planted in classes 4 and 5, so what is the maximum number of trees planted in class 3?
26. A runs 13 kilometers per hour, B runs 11 kilometers per hour, and B runs 20 minutes more than A. As a result, B runs 2 kilometers more than A. How much did B run in total***? How many kilometers did B run in total***?
27. There are two cylindrical containers of equal height A and B, with inner radii of 6 and 8 centimeters respectively. Container A is full of water, container B is empty, the container A in all the water poured into the container B, measured the depth of water in the container B than the container height of 7/8 is also lower than 2 cm. What is the height of the container in centimeters?
28. 104 tons of goods, with a load of 9 tons of car transport. It is known that the car takes 1 hour to make each round trip, but in fact the car is loaded with 1 ton more each time, so how many hours ahead of schedule can it be completed.
29. teacher, apprentice two people on the first day *** processing parts 225, the second day of the new process, the master processing parts than the first day increased by 24%, the apprentice increased by 45%, two people *** processing parts 300, the next day the master processed how many parts? How many parts did the apprentice process?
30. Endeavour Primary School organized the sixth grade students to the Hundred Flowers Mountain camping exercise, the trip increased by 2 kilometers per day. It took 4 days to get there and 3 days to get back. How many kilometers is the school from Hundred Flowers Mountain?
Primary school math application problems comprehensive training (04)
31. a place to collect the standard of electricity is: monthly electricity consumption does not exceed 50 degrees, 50 cents per degree; if more than 50 degrees, the excess part of the charge at 80 cents per degree. Monthly user A than user B to pay 3 yuan 3 cents more electricity, this month, A, B each used how many degrees of electricity?
32. Master Wang plans to use 2 hours to process a batch of parts, when there are still 160 parts left, the machine malfunctioned, the efficiency is 1/5 lower than the original, the result is more than the original plan to delay the completion of the task in 20 minutes, how many parts of this batch?
33. Mom gave Hong Hong some money to buy New Year's cards, there are A, B, C three kinds of New Year's cards, A kind of card 1.20 yuan each. There are three kinds of cards: A, B and C. A card costs 1.20 dollars each. With this money, it takes 8 more cards to buy A than B, and 6 more cards to buy B than C. How much money did mom give Hong Hong? How much money did mom give Hong Hong? How much is each card of type B?
34. An old man has five sons and three houses, and before he dies, he makes a will giving one house to each of his three sons. As compensation, the three sons who got the house each put up 1200 yuan, equally divided to the two sons who did not get the house. Everyone said this distribution is fair and reasonable, so the value of each house is how many dollars?
35. Xiaoming and Xiaoyan have less than 20 picture books. If Xiaoming gives Xiaoyan A book, Xiaoming's book is twice as much as Xiaoyan's; if Xiaoyan gives Xiaoming A book, Xiaoming's book is three times as much as Xiaoyan's. How many books do Xiaoming and Xiaoyan have each? How many picture books do Xiaoming and Xiaoyan have?
36. There are 160 red, yellow and white balls***. If you take out 1/3 of the red balls, 1/4 of the yellow balls, 1/5 of the white balls, there are 120 left; if you take out 1/5 of the red balls, 1/4 of the yellow balls, 1/3 of the white balls, there are 116 left, ask (1) how many of the original yellow balls? (2) How many red balls and white balls were there?
37. The sum of the ages of the father, brother and sister is 64, and the sister is 9 when the father's age is three times the brother's age. When brother's age is twice sister's age, dad is 34 years old. What is the age of each of the three persons now?
38. B is between two places A and C. A goes from B to A. A goes from B to A to deliver a letter. 10 minutes after B leaves, B goes from B to deliver another letter. Ten minutes after B's departure, C realizes that A and B have just taken the two letters upside down, so he rides his bike from B to catch up with A and B in order to turn the letters around. Known that the speed of A and B are equal, C's speed is three times the speed of A and B. How much time does it take for C to return to B from the start to turn the letters around?
39. A, B two workshops *** have 94 workers per day *** processing 1998 bamboo chairs. Due to differences in equipment and technology, workshop A can only produce an average of 15 bamboo chairs per worker per day, while workshop B can produce an average of 43 bamboo chairs per worker per day. How many more bamboo chairs does workshop A produce per day than workshop B?
40. A walks home from school in 10 minutes and B walks home from school in 14 minutes. It is known that the distance that B goes home is 1/6 more than the distance that A goes home, and A walks 12 meters per minute more than B. How many meters does B go home?
Primary school math application problems comprehensive training (05)
41. a cost of 72 yuan per piece of merchandise, the original pricing to sell, 100 pieces can be sold every day, each piece of profit for the cost of 25%, and later priced at 90% of the sale of the daily sales increased to the original 2.5 times, according to such calculations, the daily profit than the original increase of a few dollars?
42. A, B two trains speed ratio is 5: 4. B car first, from the B station to the A station, when going to the B station 72 kilometers away from the place, the A car from the A station to the B station, the two trains meet the place from the A, B two stations distance ratio is 3: 4, then the A, B distance between the two stations for how many kilometers?
43. There are 35 monkeys*** and they go to pick peaches together. In the absence of the king, a big monkey can pick 15 kilograms of peaches in an hour, and a small monkey can pick 11 kilograms of peaches in an hour. When the king is there to supervise, each monkey, big or small, can pick 12 kilograms per hour. One day, after 8 hours of picking, of which only the first and last hours were supervised by the king, *** picked 4400 kg of peaches. How many small monkeys are there in this colony***?
44. A math competition has a first and second prize. It is known that (1) the ratio of the number of winners in schools A and B is 6:5. (2) the sum of the number of second prizes won by schools A and B in the coming year is 60% of the total number of winners in the two schools. (3) The ratio of the number of people winning the second prize in schools A and B is 5:6. What is the percentage of the total number of people winning the second prize in school A to the total number of people winning the prize in that school?
45. It is known that the ratio of the speeds of Xiaoming and Xiaoqiang on foot is 2:3, and the ratio of the speeds of Xiaoqiang and Xiaogang on foot is 4:5. It is known that Xiaogang walks 420 meters more than Xiaoming in 10 minutes, so how many meters does Xiaoming walk less than Xiaogang in 20 minutes?
46. A batch of parts is scheduled to be machined 15 times a day for a number of days. When 3/5 of the processing task is completed, a new technology is used to increase the efficiency by 20%. As a result, the completion of the task 10 days ahead of the time, this batch of parts *** how many?
47. A and B run a 10,000 meter race on a 400 meter circular track. Two people from the start at the same time in the same direction, the beginning of the speed of A 8 m / s, B's speed of 6 m / s, when the A each time after catching up with B, A's speed is reduced by 2 meters per second, B's speed is reduced by 0.5 meters per second. This continues until A realizes that B is catching up with him from behind for the first time, and then both of them increase their speed by 0.5 m/s until they reach the finish line. How many meters is the other person from the finish line when the leader reaches the finish line?
48. When Ming goes from home to school, if he walks 1.5 kilometers per hour more than the original, he walks the distance in 4/5 of the original time; if he walks 1.5 kilometers per hour less than the original, he walks the distance in a fraction of a second more than the original time?
49. The sum of the present ages of A, B, C and D is 64 years. When A is 21 years old, B is 17 years old, and when A is 18 years old, C is three times as old as D. What is D's age now? What is D's age now?
50. A batch of parts is scheduled to be machined 30 times a day. When 1/3 of the parts have been processed, the efficiency is increased by 10% due to improved technology, and the job is completed 4 days ahead of schedule. How many parts *** are in this batch?
Primary school math application problems comprehensive training (06)
51. escalator to a uniform speed upward, a boy and a girl at the same time from the escalator upward, the boy's speed is 2 times the girl, the boy is known to go to the top of the escalator 27, while the girl went to the top of the 18 steps. How many steps of the escalator are exposed?
52. Two piles of apples weigh the same, the first pile is sold for 2/3 and the second pile is sold for 50 kg. If the apples left in the first pile are less than those left in the second pile, how many kilograms of apples are left in the two piles?
53. Two cars A and B start from A at the same time, and keep traveling back and forth between A and B. If you know that the speed of car A is faster than that of car B, then you have to drive back and forth between the two. It is known that the speed of car A is faster than car B, and the first and second encounter after the departure of the two cars are miscellaneous on the way to C. How many times the speed of car A is car B?
54. A boat from A to B and back in 2 hours, back to the water, more than the speed of going 8 kilometers per hour, so the second hour than the first hour more than 6 kilometers. Find the distance between places A and B.
55. A, B, two cars from A, B, respectively, and in A, B, between the two places constantly traveling back and forth. Known as the speed of car A is 15 km / h, A, B, two cars met for the third time and the fourth meeting place 100 km difference. Find the distance between the two places A and B.
56. A person walks up an escalator from the top to the bottom in 7 minutes and 30 seconds, and he walks up the escalator from the bottom to the top in 1 minute and 30 seconds. If the person does not walk, how much time does it take to go from the bottom to the top on the escalator? If there is a power failure, how much time will it take the person to go from the bottom to the top along the escalator?
57. A, B two cylindrical containers, the ratio of the bottom area of 5:3, A container of water depth of 20 centimeters, B container of water depth of 10 centimeters. Then fill the two containers with the same amount of water, so that the depth of water in the two containers is equal. How many centimeters deep is the water?
58. A, B two places are 207 kilometers away from each other, A, B two cars at 8:00 at the same time from A to B, the speed of 60 km / h, 54 km / h, respectively, C 8:30 from B to A, the speed of 48 km / h. C and A, B two cars at the same time from A to B, the speed of 60 km / h, 54 km / h, respectively. What is the time and minute when car C is equidistant from cars A and B?
59. The perimeter of a rectangle is 130 centimeters. If its width is increased by 1/5 and its length is decreased by 1/8, a new rectangle of the same perimeter is obtained. Find the area of the original rectangle.
60. There is a rectangle whose length to width ratio is 5:2 and whose diagonal is 29 centimeters long, find the area of this rectangle.
Primary school math application problems comprehensive training (07)
61. There is an orchard, last year the fruit trees than the fruit trees do not bear fruit 2 times more than 60 trees, this year there are 160 fruit trees bear fruit, this time the fruit trees is exactly 5 times the fruit trees do not bear fruit. How many fruit trees are there in the orchard***?
62. Xiaoming walks from A to B, and Li Gang rides a motorcycle from B to A at the same time. 48 minutes later, they meet, and Li Gang arrives at A and immediately returns to B, catching up with Xiaoming 16 minutes after the first encounter. If Li Gang keeps traveling back and forth between A and B, how many times does Li Gang*** catch up with Ming when Ming arrives at B?
63. For the same 100-meter walk, Ming takes 180 steps and his father takes 120 steps. Father and son start from the same place in the same direction at the same time, if the time taken for each step is the same, how many more steps does the father have to take to meet Ming when he walks out 450 meters and then walks back?
64. A ship sailing between two ports with a water speed of 6 km/h takes 4 hours to sail with the water and 7 hours to sail against the water, find the distance between the two ports.
65. There are A, B, C three cars, each at a certain speed from A to B, B than C 10 minutes later than the departure, 40 minutes after the departure to catch up with the C; A than B and 10 minutes later than the departure, 60 minutes after the departure to catch up with the C, ask the A departure a few minutes to catch up with the B?
66. A and B work together to complete a job, due to good cooperation, A's work efficiency than when doing it alone to improve 1/10, B's work efficiency than when doing it alone to improve 1/5, A and B work together to complete the work in 6 hours, if A alone to do it in 11 hours, then B alone to do it in how many hours?
67. Five students A, B, C, D and E are standing in a horizontal row holding 20 small flags in their hands***. It is known that the student standing to the right of C*** is holding 11 flags, the student standing to the left of B*** is holding 10 flags, the student standing to the left of D*** is holding 8 flags and the student standing to the left of E*** is holding 16 flags. Who are the five students in order from left to right? How many small flags does each one hold?
68. Ming ran a lap on a 360-meter-long track in a circular pattern. Knowing that he ran 5 meters per second for the first half of the race and 4 meters per second for the second half, how long did it take him to cover the second half of the race?
69. Xiaoying and Xiaoming in order to measure the length and speed of the passing train, they took two stopwatches, Xiaoying used a watch to note that the train passed in front of him in 15 seconds, Xiaoming used another watch to note that from the front of the car over the first pole to the end of the car over the second pole in 18 seconds, known as the distance between the two poles is 60 meters, the train's full length and speed. length and speed of the train.
70. Ming walks the first half of the way from home to school and takes the bus the second half; he takes the bus the first 1/3 of the way from school to home and walks the second 2/3 of the way. As a result, it takes him 20 minutes longer to get to school than it does to get home. How many kilometers does Ming travel from home to school?
Primary school math application problems comprehensive training (08)
71. math practice *** held 20 times, *** out of the test 374 questions, each time the number of questions is 16, 21, 24 asked out of 16, 21, 24 questions respectively, how many times?
72. A whole number is divided by 2 and the remainder is 1, the resulting quotient is divided by 5 and the remainder is 4, and the resulting quotient is divided by 6 and the remainder is 1. What is the remainder of the number when you divide this whole number by 60?
73. The pioneers planted twice as many apple saplings as pear saplings in the schoolyard. If each of them plants 3 pear saplings, there are 2 left. If each of them plants 7 apple saplings, there are 6 left. How many pioneers are there in ****? How many apple and pear saplings are there ***?
74. A person driving a car from City A to City B to line 200 kilometers, the beginning of his 56 km / h speed, but on the way due to car trouble stopped to repair half an hour, in order to arrive on time, he must increase the speed of 14 km / h to finish the journey, he repaired the car from the place of the A city how many kilometers?
75. A, B two people were from A, B two places at the same time, traveling in the direction of each other, B's speed is a 2 / 3, the two met and continued to move forward, A arrived at B, B arrived at A and immediately returned, known as the two met for the second time the location of the location from the first meeting is 3000 meters, the distance between A, B two places.
76. A boat round trip between A, B two ports, known as the speed of the boat in static water for 9 km / h, usually retrograde and downstream of the time used by the ratio of 2: 1. One day due to rain, the current speed of the original two times the speed of the boat back and forth*** with 10 hours, ask A, B two ports how many kilometers apart?
77. A school entrance exam, determine the admission score line, apply for students, only 1/3 were admitted, the average score of those admitted is 6 points higher than the admission score line, not admitted to the students whose average score is 15 points lower than the admission score line, the average score of all candidates is 80 points, ask the admission score line is how many points?
78. A group of students moving bricks, if there are 12 people each move 7 blocks, the rest of each person to move 5 blocks, then the last remaining 148 blocks; if there are 30 people each move 8 blocks, the rest of each person to move 7 blocks, then the last remaining 20 blocks. Ask how many students ****? How many bricks?
79. A, B two cars were from A, B two places at the same time traveling in the same direction, known as the speed of car A and car B speed ratio of 4:3, C in A, B between A, B, A, B two cars to reach the C time were 8:00 a.m. and 3:00 p.m., ask A, B two cars meet is what time?
80. A chess tournament, the scoring method is, the winner scored 2 points, the loser scored 0 points, and chess two people each scored 1 point, each player with the other players each game once, now know that the players in the boys are 10 times the number of girls, but their total score is only 4.5 times the score of the girls, ask *** how many girls competed? How many points did the girls *** score?
Elementary math application problems comprehensive training (09)
81. There are a number of natural numbers, their arithmetic mean is 10, if the largest one is removed from these numbers, the remaining arithmetic mean is 9; if the smallest one is removed, the remaining arithmetic mean is 11, how many of these numbers are there at most? What is the maximum value of the largest of these numbers?
82. There are 35 pioneers in a class and 23 boys in this class. How many more girls are pioneers than boys are non-pioneers in this class?
83. Xiaodong plans to visit Zhoukoudian to see the ruins of the apes. If he travels by car at 40 km/h, then he arrives 3 hours earlier than if he goes by bike, and if he goes on foot at 8 km/h, then he arrives 5 hours later than if he goes by bike. How many kilometers is it from Xiaodong's starting point to Zhoukoudian?
84. A, B two boats sailing on the river 90 kilometers apart, if the opposite direction, 3 hours to meet, if the same direction, then 15 hours boat A catch up with the boat B. Seek in still water A, B two boat speed.
85. two classes of second grade **** there are 90 students, of which there are 71 pioneers, a class of pioneers accounted for 75% of the class, the second class of pioneers accounted for the number of 5/6 of the class. the number of class of pioneers than the number of class of pioneers more than the number of class of pioneers a few people?
86. A container has been filled with water and there are three balls: large, medium and small. The first time the small ball is sunk into the water, the second time the small ball is taken out and the medium ball is sunk into the water, the third time the medium ball is taken out and the small ball is sunk into the water along with the large ball. It is now known that each time the amount of water overflowing from the container is: the first time is 1/2 of the second, the third time is 1.5 times of the second. Find the ratio of the volumes of the three balls.
87. A man took 2 hours to cross a mountain and 2.5 hours to return, and he went up the mountain at a speed of 3,000 m / h, and down the mountain at a speed of 4,500 m / h. How much did it take to cross the mountain? How many meters did it take to go over the mountain?
88. steel raw materials each 7.3 meters long, each set of steel shelves with a length of 2.4 meters, 2.1 meters and 1.5 meters of steel each section. Now you need to tie up 100 sets of rebar racks, at least how many pieces of raw material will be used?
89. There is a piece of copper-zinc alloy, in which the ratio of copper and zinc 2: 3. It is now known to add 6 grams of zinc, melted **** to get a new alloy of 36 grams of the new alloy of copper and zinc in the ratio of how much?
90. Xiaoming usually always walk to school, one day he wanted to exercise, the first 1/3 of the distance fast running, the speed is 4 times the walking speed, the latter part of the distance jogging, the speed is 2 times the walking speed. In this way, Xiaoming arrived at school 35 minutes earlier than usual. How many minutes does it take for Xiaoming to walk to school?
Primary school math application problems comprehensive training (10)
91. A, B, C three people, A's age than the age of B two times the age of three years older, B's age than the age of C two times the age of two years younger, the age of the three people and the sum of the age of 109 years old, respectively, to find the age of A, B, C.
92.
92. The fast car with a speed of 60 km / h from station A to station B, 1.5 hours later, the slow car with a speed of 40 km / h from station B line station A, . When the two cars meet, the meeting point is 70 km from the midpoint of the two stations. A, B two stations are separated by how many kilometers?
93. A, B two cars have left the school at the same speed to the museum, known as 8:32 minutes the distance between car A and the school is three times the distance between car B and the school, 8:39 minutes the distance between car A and the school is two times the distance between car B and the school, find the time car A left the school.
94. There is a work group, when each worker in their respective jobs, 7 hours to produce a batch of parts, if the exchange of workers A, B's position, other people do not change, then can be 1 hour ahead of time, to complete the batch of parts, if the exchange of workers C, D's position, other people are unchanged, but also ahead of time, 1 hour, ask if the simultaneous exchange of A and B, C and D's position, other people do not change, then the completion of this batch of parts required to complete the batch of parts. remain unchanged, then how long will it take to complete the batch of parts.
95. With 10 rectangular blocks 7 cm long, 5 cm wide and 3 cm high, put together a rectangle, what is the minimum surface area of this rectangle?
96. The public round only two kinds of tickets: individual tickets 5 yuan each, 10 people a group ticket 30 yuan each, buy more than 10 group tickets can be discounted by 10%. (1) A unit of 45 people to visit the park, according to the above provisions of the ticket, the minimum amount of money payable? (2) B unit 208 people to visit the park, according to the above provisions of the ticket, at least how much money payable?
97. A, B, C, three people, to take an exam, *** scored 260 points, known as the A score of 1/3, B score of 1/4 and C score of half minus 22 points are equal, then C score how much?
98. a project, a, b two people work together for 4 days, and then by b alone to do 5 days to complete, known as a more than b per day to complete this project 1/30. a, b alone to do this project each need a few days?
99. There are two candles, long and short, (the same time in the same length of combustion), the sum of their lengths is 56 centimeters, they will be lit at the same time for a period of time, the long candle with the short candle before the lighting of the same length, the length of the short candle at this time and exactly the length of the long candle is 2 / 3. How long was the long candle before the lighting of the long candle?
100. A batch of apples is divided equally among 20 baskets. How many baskets can be saved if each basket contains 1/9 more apples?
Elementary School Math Application Problems Comprehensive Training(11)
101. Xiaoming bought 1 pen, the money used is 0.5 yuan more than half of the total money brought; bought a ballpoint pen, the money used is 0.5 yuan less than half of the money left over after the purchase of the pen; and bought 2.8 yuan of the book, the last remaining 0.8 yuan. How many dollars did Xiaoming bring?
102. The son is 6 years old, and the father's age 10 years ago is equal to the son's age 20 years from now. What year is it when the father's age is exactly twice the son's age?
103. On a wire 12 meters long, a yellow beetle crawls from the right end to the left end at a speed of 15 centimeters per minute at 8:20; a red beetle and a blue beetle crawl from the left end to the right end at a speed of 13 centimeters and 11 centimeters per minute, respectively, at 8:30; at what moment is the red beetle exactly in the middle of the blue beetle and the yellow beetle?
104. A People's Liberation Army (PLA) troop from the garrison rushed to a certain place by car to fight against floods, if the speed of the car than the original increase of 1/9, it can be 20 minutes earlier than the scheduled time to arrive; if the original speed of the first 72 kilometers, and then the speed of the car than the original increase of 1 / 3, it can be 30 minutes earlier than the scheduled time to arrive. How many kilometers did the PLA unit travel?
105. A boat makes a round trip from pier A to pier B in 4 hours, and when it comes back, it travels 12 kilometers more per hour downstream than it did when it went there. Thus the last 2 hours are 18 km more than the first 2 hours, so how many kilometers is the distance between piers A and B?
106. The ratio of the number of students in classes A and B is 5:4. If 9 students are transferred from class B, then class A has 2/3 more students than class B. How many students are there in class B?
107. two piles of coal A and B *** weigh 78 tons, 25% from pile A to pile B, then the ratio of the weight of pile B to pile A is 8:5. how many tons of coal each originally?
108. a job, A alone to do to 20 days to complete, B alone to do to 12 days to complete, if this job first by the A team to do a number of days, and then by the B team to do the end of the two teams * * * used 14 days, A team to do how many days?
109. A motor factory plans to produce a number of motors, the beginning of the production of 50 units per day, the production of 1/5 of the plan, due to technological innovation so that the efficiency of the work increased by 60%, so that the completion of the task than the plan ahead of schedule in 3 days, the production of this batch of motors, the task is how many units?
110. Two numbers are divided by 9 and 4, if the divisor, divisor are expanded to 3 times the original. Then the sum of divisor, divisor, quotient and remainder is equal to 2583. what are the original divisor and divisor?
Comprehensive training of elementary school math application problems (12)
1. 3/7 × 49/9 - 4/3
2. 8/9 × 15/36 + 1/27
3. 12 × 5/6 - 2/9 × 3
4. 8 × 5/4 + 1/4
5. 6÷ 3/ 8 - 3/8 ÷ 6
6. 4/7 × 5/9 + 3/7 × 5/9
7. 5/2 - (3/2 + 4/5)
8. 7/8 + (1/8 + 1/9)
9. 9 × 5/6 + 5/6
10. 3/4 × 8/9 - 1/3
11. 7 × 5/49 + 3/14
12. 6 × (1/2 + 2/3)
13. 8 × 4/5 + 8 × 11/5
14. 31 × 5/6 - 5/6
15. 9/7 - (2/7 - 10/21) < /p>
16. 5/9 × 18 - 14 × 2/7
17. 4/5 × 25/16 + 2/3 × 3/4
18. 14 × 8/7 - 5/6 × 12/15
19. 17/32 - 3/4 × 9/24
20. 3 × 2/9 + 1/3
21. 5/7 × 3/25 + 3/7
22. 3/14 × × 2/3 + 1/6
23. 1/5 × 2/3 + 5/6
24. 9/22 + 1/11 ÷ 1/2
25. 5/3 × 11/ 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 × 21/16 + 1/2