Looking for 50 math application questions in the first volume of junior high school, and the answers (the process must be complete)

1. To transport 29.5 tons of coal, first use a truck with a load of 4 tons to transport it 3 times, and the rest with a truck with a load of 2.5 tons. How many more times will it take to complete?

It will take x times to finish

29.5-3*4=2.5x

17.5=2.5x

x=7

It has to be transported 7 times to complete

2. The area of ??a terraced field is 90 square meters, the upper base is 7 meters, and the lower base is 11 meters. How many meters is it high? ?

Its height is x meters

x(7 11)=90*2

18x=180

x=10

Its height is 10 meters

3. A certain workshop plans to produce 5,480 parts in April. It has been in production for 9 days, and the production plan can be completed by producing 908 more units. How many units were produced per day on average during these 9 days?

The average production of x pieces per day during these 9 days

9x 908=5408

9x=4500

x=500

An average of 500 units were produced every day during these 9 days

4. Two vehicles A and B drove towards each other at the same time from two places 272 kilometers apart. Three hours later, the two vehicles were still 17 kilometers apart. A travels 45 kilometers per hour. How many kilometers does B travel per hour?

B travels x kilometers per hour

3(45 x) 17=272

3(45 x)=255

45 x=85

x=40

B travels 40 kilometers per hour

5. There are two classes in the sixth grade of a school, the first grade mathematics The average score is 85 points. It is known that there are 40 people in Class 6 (1), and the average score is 87.1 points; there are 42 people in Class 6 (2), what is the average score?

The average score is x points

40*87.1 42x=85*82

3484 42x=6970

42x=3486

p>

x=83

The average score is 83 points

6. The school bought 10 boxes of chalk. After using 250 boxes, there were 550 boxes left. On average, How many boxes per box?

Average x boxes per box

10x=250 550

10x=800

x=80

An average of 80 boxes per box

7. There are 200 students in the fourth grade ***. During extracurricular activities, 80 girls go to skip rope. Boys are divided into 5 groups to play football. How many people are in each group on average?

Average x people per group

5x 80=200

5x=160

x=32

An average of 32 people per group

8. The canteen shipped 150 kilograms of rice, which was 30 kilograms less than three times the flour shipped. How many kilograms of flour are delivered to the canteen?

The canteen transported x kilograms of flour

3x-30=150

3x=180

x=60

The canteen brought 60 kilograms of flour

9. There are 52 peach trees in the orchard and 6 rows of pear trees. There are 20 more pear trees than peach trees.

How many pear trees are there on average in each row?

On average, there are x pear trees in each row

6x-52=20

6x=72

x=12

On average there are 12 pear trees in each row

10. The area of ??a triangular piece of land is 840 square meters, the base is 140 meters, and how many meters is the height?

The height is x meters

140x=840*2

140x=1680

x=12

The height is 12 meters

11. Master Li bought 72 meters of cloth, which can be used to make 20 adult clothes and 16 children's clothes. Each piece of adult clothing uses 2.4 meters, and each piece of children's clothing uses how many meters of cloth?

X meters of cloth per piece of children's clothing

16x 20*2.4=72

16x=72-48

16x=24

x=1.5

Each piece of children’s clothing uses 1.5 meters of cloth

12. Three years ago, the mother was 6 times as old as her daughter. This year, the mother is 33 years old. How old is your daughter this year?

My daughter is x years old this year

30=6(x-3)

6x-18=30

6x=48

p>

x=8

My daughter is 8 years old this year

13. How long does it take for a car traveling at 50 kilometers per hour to catch up with the car that drove out 2 hours ago? A car traveling at 40 kilometers per hour?

Requires x time

50x=40x 80

10x=80

x=8

Requires 8 Time

14. Xiaodong went to the fruit store and bought 3 kilograms of apples and 2 kilograms of pears. He paid 15 yuan. 1 kilogram of apples is 0.5 yuan more expensive than 1 kilogram of pears. Apples and pears are each 0.5 yuan per kilogram. How much?

Apple x

3x 2(x-0.5)=15

5x=16

x=3.2

Apple: 3.2

Pear: 2.7

15. Two cars A and B start from A and B at the same time, traveling towards each other. A travels 50 kilometers per hour , B travels 40 kilometers per hour, and A reaches the midpoint 1 hour earlier than B. How many hours does it take for A to reach the midpoint?

A reaches the midpoint in x hours

50x=40(x 1)

10x=40

x=4

A reaches the midpoint in 4 hours

16. Two people, A and B, set off from places A and B at the same time, traveling towards each other, and meet each other in 2 hours. If A starts from point A and B starts from point B at the same time, traveling in the same direction, then A will catch up with B 4 hours later. It is known that the speed of A is 15 kilometers/hour, find the speed of B.

B’s speed x

2(x 15) 4x=60

2x 30 4x=60

6x=30

p>

x=5

B’s speed is 5

17. Two ropes of the same length are cut off from the first one to 15 meters, and the second rope is 3 meters longer than the remaining length of the first rope. How many meters long are the two ropes?

It turns out that the two ropes are each x meters long

3(x-15) 3=x

3x-45 3=x

2x=42

x=21

It turns out that the two ropes are each 21 meters long

18. A school bought 7 basketballs and 10 footballs and paid 248 yuan.

It is known that the price of each basketball and three footballs is equal. How much are each basketball and football?

Each basketball x

7x 10x/3=248

21x 10x=744

31x=744

x=24

Each basketball: 24

Each football: 8

1. A pool holds 84 tons of water, and there are A and B. There are two water pipes. Pipe A discharges 2.5 tons of water per hour, and pipe B discharges 3.5 tons of water per hour. If pipe A is opened first, and then pipe B is opened 2 hours and 24 minutes later, how many hours after pipe A is opened can the water in the pool be drained?

2. The correspondent sent a message from point A to point B, and then immediately returned to point A. It took *** 3 hours and 52 minutes, with a speed of 30 kilometers per hour when going, and a speed of 28 kilometers when returning. / time, find the distance between A and B.

3. A walks 5 kilometers per hour, and B rides to chase A 2 hours after departure.

(1) If B’s speed is 20 kilometers/hour, how long does it take for B to catch up with A?

(2) If you are asked to catch up with A when B has walked 14 kilometers, what is B’s speed?

1. The thoughtful mother went to the market to buy fruit. She first bought 2.5KG of apples for 3.5 yuan, and also planned to buy 3KG of oranges. The unit price of oranges is 1.6 times that of apples. How much does it cost to buy oranges?

2. Xiaohua borrowed a 120-page storybook, and she read 36 pages in 3 days. If you can only borrow it for 8 days, how many pages should you read every day starting from the 4th day?

3. The canteen bought 360 kilograms of rice and planned to eat 30 kilograms every day. It actually took 3 days longer than planned. How many kilograms of this batch of rice were actually eaten per day?

4. Build a 340-kilometer road, with an average of 20 kilometers per day in the first two days. The remaining part needs to be completed in 4 days. How many kilometers is repaired per day on average?

5. Two cars A and B drove away from each other at the same time from two places 396 kilometers apart. Car A travels 85.8 kilometers per hour, and car B travels 90.2 kilometers per hour. After how many hours did the car meet?

6. A transportation team has to transport 84,000 bricks. If it transports 0.35 bricks per hour, it can transport them all on time. If everything is to be shipped 4 hours ahead of schedule, how many thousands of dollars should be shipped per hour?

7. A certain workshop can produce 120 parts of type A, 100 parts of type B, or 200 parts of type C every day. Take 3, 2, and 1 parts of A, B, and C respectively. Each can be used as a set. It is now required to produce the largest number of complete sets of products within 30 days. How many days should each of the three parts A, B, and C be arranged for production?

8. A mathematics reading book costs 6.25 yuan, and a Chinese reading book costs 5.86 yuan. How much does two books cost per ***?

9. A watermelon weighs 4.86 kilograms and a cantaloupe weighs 3.5 kilograms. How many kilograms more does a watermelon weigh than a cantaloupe?

One-step multiplication and division problems with two decimals 1 A kind of wool costs 48.36 yuan per kilogram. How much yuan should you pay to buy 3 kilograms? How about buying 0.6kg?

2. A professional group of sericulture raises 21 spring silkworms and produces 1,240 kilograms of cocoons in one day. On average, how many kilograms of cocoons are produced per cocoon?

3. Two-step calculation problem with three known conditions 1. Xiaohong read a storybook for 5 days, reading 12 pages every day, and there were 38 pages left. How many pages does this book have? (Draw a line segment diagram)

2. The canteen brought 3 bags each of flour and rice. Each bag of flour weighs 25 kilograms and each bag of rice weighs 50 kilograms. How many kilograms of flour and rice are shipped?

3. The militiamen used 250 rounds of bullets for target shooting in the first time, 320 rounds of bullets in the second time, and 180 rounds less than the total of the first two times in the third time. How many rounds of bullets were used in the third time?

4. Two-step calculation problem with two known conditions

1. The school bought 45 boxes of colored chalk, and bought 15 boxes more white chalk than colored chalk. How many boxes of chalk should I buy per ***?

2. An empty basket weighs 2 kilograms. Put 32 kilograms of peanuts into the basket.

How many times does the basket of peanuts weigh more than the empty basket?

5. Multiple multiplication problems

1. The grain store transported two trucks of flour, each truck containing 80 bags of 25 kilograms each. How many kilograms of flour does this grain store transport? (Answer in two ways)

2. The third-grade students went to the vegetable garden to collect cabbage. They were divided into 4 groups, with 11 people in each group. Each person collected an average of 45 kilograms. How many kilograms of cabbage can be harvested per day?

1． The fertilizer factory plans to produce 7,200 tons of fertilizer. It has been in production for 4 months. The average monthly production of fertilizer is 1,200 tons. The remaining monthly production is 800 tons. How many months will it take to complete the production?

2. The plastic factory planned to produce 1,300 plastic modules and produced 780 pieces in 6 days. Based on this calculation, how many days will it take to complete the remaining production?

3. Master Li produced 252 parts in 4 hours in the morning, and worked for another 3 hours in the afternoon at this rate. How many parts does Master Li produce on this day?

4. The cement plant plans to produce 3,600 tons of cement and it will take 20 days to complete. The actual production is 20 tons more per day than planned. How many days does it actually take to complete the task?

5. A pile of 3.6 tons of coal is planned to be burned for 10 days. After improving the stove, 0.06 tons are saved per day compared with the original plan. How many days can this pile of coal be burned now?

6. Places A and B are 420 kilometers apart. A passenger bus plans to travel from place A to place B for 7 hours. I actually traveled 10 kilometers per hour more than originally planned. How many hours did it actually take to arrive?

7. Xiaoqiang returns to school from home. If he walks 50 meters per minute, he will return to school in 12 minutes. If he walks 10 meters more per minute, how early can he return to school?

8. To build a 6.4-kilometer-long road, the average construction time is 1.2 kilometers per month in the first three months, and the remaining 1.4 kilometers per month. How many months will it take to complete?

9． Xiao Ming spent 10.2 yuan on stationery and bought 6 pencils at 0.45 yuan each. The remaining money bought ballpoint pens at 2.5 yuan each. How many pens can he buy?

10. The garment factory originally planned to make 120 suits, with each suit using 4.8 meters of fabric. After improving the cutting method. Each suit saves 0.3 meters of cloth. How many suits can be made from the original cloth?

11． A storybook originally had 576 words per page and 25 pages. When reprinting, the font size was reduced and only 18 pages were required. How many more words are there on each page now than before?

12. A passenger bus and a freight train depart from two places A and B opposite each other at the same time. The passenger bus travels 80 kilometers per hour and the freight train travels 60 kilometers per hour. After 5 hours, the two vehicles meet. How many kilometers is the railway between A and B?

13. Two engineering teams are working together to dig a 1,500-meter tunnel at the same time. Engineering team A starts working at one end and digs 14 meters per day. Engineering team B starts working at the other end and digs 16 meters per day. How many days will it take for the tunnel to be dug?

14. A and B type a 7,000-word manuscript at the same time. A types 600 words per hour, and B types 200 words more per hour than A. How many hours will it take to complete the task?

15． Xiao Ming and Xiao Qiang walk in opposite directions at the school gate after school. Xiao Ming walks 70 meters per minute and Xiao Qiang walks 68 meters per minute. How many meters are they apart after 5 minutes?

16. The distance between A and B is 630 kilometers. Two hours after the passenger car leaves from A, the truck drives in the opposite direction from B. It is known that the passenger car travels 65 kilometers per hour, and the truck travels 65 kilometers per hour. Travel 60 kilometers per hour.

How many hours after the truck drove out did it meet the passenger car?

I wish your grades will get better and better! ~~! ! ~! ~Hehe

4. A and B practice walking on a 400-meter circular track. B walks 80 meters per minute. A’s speed is 1 and 1/4 of B’s. , now A is 100 meters in front of B, how many minutes will it take for the two to meet for the first time?

1. There is a three-digit number. Its units digit is 3 times smaller than 4 times of the number in the hundreds place. The number in the ones place is 1 larger than 3 times of the number in the hundreds place. If The number in the tens place of this three-digit number is swapped with the number in the hundreds place to get a new number. Then the original three-digit number is 270 less than the new number. Find the original three-digit number.

2. The school has a 4-story teaching building with 6 classrooms on each floor. There are 3 doors to enter and exit the building (two main doors of the same size and a side door). Security inspection At that time, this door was tested; when a main door and a side door were opened at the same time, 400 students could pass through in 2 minutes. If a front door can pass an average of 40 more students per minute than a side door.

(1) Find the average number of students who can pass through one main entrance and one side entrance per minute?

(2) During the inspection, it was found that in an emergency, the efficiency of going out was reduced by 20% due to overcrowding of students. Safety regulations: In an emergency, all students in the building should pass through these 3 doors within 5 minutes. Evacuate safely. Assuming that each classroom in this teaching building has a maximum of 45 students, ask: Do these three doors comply with safety regulations? Why?

3. A and B travel from city A to city B. A walks 4 kilometers per hour, and B rides a bicycle 8 kilometers per hour. B starts half an hour after A. , two people arrive at city B at the same time, find the distance between cities A and B.

4. Yuren Middle School requires several students to cancel their registration. If there are 4 people living in each dormitory, there will be 20 people left; if there are 8 people living in each dormitory, one dormitory will be full and the other dormitories will be full. Q: How many dormitories does the middle school have? How many students are required to live on campus?

5. A one-minute call on a mobile phone costs 3 cents more than a text message. It is known that the number of minutes spent on a call costing 8 yuan is equal to the number of messages spent 2 yuan on. Ask the mobile phone What is the cost per minute of calls and the cost of 1 message?

6. Xiaoqiang and Xiaohua practice running. Xiaoqiang runs 50 meters more per minute than Xiaohua. The time it takes Xiaoqiang to run 750 meters is equal to the time it takes Xiaohua to run 600 meters. Ask them what speed?

7. The distance between A and B is 80 kilometers. 3 hours after a bus leaves from A, a car also leaves from A. Its speed is The bus × car is three times faster than the bus × car. It is known that the car arrives at point B 20 minutes later than the bus × car. What are the speeds of the two cars?

8. There is a 400-meter circular track on the school playground. A and B start from the same place in opposite directions at the same time. A’s speed is x meters per second, and B’s speed is x meters per second. Ym, how much time passed before they met for the third time?

9. A project takes 10 days to do by A alone, and 12 days for B to do it alone. C 15 days. A and C work for 3 days first. A leaves due to business, and B joins the work.

It still takes a few days to complete

1) The fruit store transports 390 kilograms of apples, bananas, and pears in one day. The weight of apples is 1.5 times that of pears, and the weight of bananas is 3/4 of pears. , how many kilograms of each of the three fruits are transported?

(2) For a tank of water, 1/2 and 5 buckets are used, and 30 is left. How many buckets of water are there in this tank?

(3) A cube of wood with an edge length of 20 cm is planed into a cylinder with the largest base diameter. What is the volume of the wood removed?

(4) A steel pipe is 10 meters long. 7/10 of it is cut off for the first time, and the remaining 1/3 is cut off for the second time. How many meters are left?

(5) Two groups assemble radios. Group A assembles 50 units every day and completes 10% of the total task on the first day. Then Group B starts assembling and assembles 40 units every day to complete this batch of tasks. How many days did Group A do it?

(6) Build a highway. After completing 2/3 of the total length, it is 16.5 kilometers away from the midpoint. How many kilometers is the total length of this highway?

(7) A master and an apprentice work together to make a batch of parts. The apprentice makes 2/7 of the total, which is 21 fewer parts than the master. How many parts are there in this batch?

(8) Two teams build a road. Team A builds 1/5 of the total length every day, and Team B works alone for 7.5 days to complete the road. If two teams study together for 2 days, and Team B studies the rest alone, how many days will it take to complete?

(9) There is a batch of fertilizer in the warehouse. The first time I took out 2/5 of the total, and the second time I took out 1/3 of the total, 12 bags less. At this time, there were 24 bags left in the warehouse, twice. ***How ??many bags were taken out?

(10) The front wheel rotates 40 times more than the rear wheel in a distance of 720 meters. If the circumference of the rear wheel is 2 meters, find the circumference of the front wheel.

(11) The number A is 1.2 times the average of the three numbers A, B and C. If the sum of the numbers B and C is 99, what is the number A?

(12) There is a project planned to employ 800 workers and be completed within 100 days. Unexpectedly, the work stopped due to an accident 35 days after it started, and continued after 25 days. If the work is to be completed within the deadline, how many more workers should be added?

(13) The fruit shop bought several kilograms of apples for 2 yuan, 1.5 kilograms, and sold them for 4 yuan, 2.5 kilograms. If the store wants to make a profit of 100 yuan, how many kilograms of fruit must the fruit store sell?

(14) The walking speeds of A, B and C are 30 meters, 40 meters and 50 meters per minute respectively. A and B are both in place A, and C is in place B. A, B and C are walking towards each other at the same time. C meets A 10 minutes after meeting B. How many meters are they apart from each other?

(15) It takes A 10 minutes to go from East Village to West Village, and B 15 minutes to go from West Village to East Village. They start walking towards each other at the same time. When they meet, they are 150 meters away from the midpoint. Find the two villages distance between. lt;/Plt; pgt;

(16) A car runs 2/5 of the distance on the first day, the remaining 1/2 on the second day, and the distance on the third day It is 1/3 less than the first day, and the remaining distance is 50 kilometers. How many kilometers is the whole journey?

(17) A passenger ship sails from Port A to Port B at a speed of 24 kilometers per hour. The cargo ship sails from Port B to Port A, taking 12 hours to complete the journey. Now they depart from each other at the same time. When they meet, the ratio of the distance traveled by the passenger ship and the cargo ship is 6:7, which is the distance between the two ports A and B.

(18) Stations A and B are 1134 kilometers apart. A passenger car and a truck leave from the two stations in opposite directions at the same time. They meet each other in 10 hours and 30 minutes. The speed of the truck is 5/7 of the speed of the passenger car. The speed of the passenger car per hour How many kilometers?

(19) The number of male employees in an assembly workshop is 40 and the number of female employees is equal to 20. It is known that there are 130 female employees in this workshop. How many male employees are less than the number of female employees?

(20) There are 25 kilograms of salt water with a salt content of 20. After adding some water, the salt content is 8. How much water was added?

(21) The three warehouses A, B and C store 307 tons of grain. After each has shipped 40 tons, the ratio of the weight of grain left in warehouse A and B is 3:5, and the weight of grain left in warehouse B and C is 3:5. The ratio is 3:4. How many tons of original grain does Bingku have?

(22) Workshops A and B have to process a batch of flour. The actual ratio of completing the planned 130 tasks between workshops A and B is 8:5. Workshop B processes 13.5 tons less flour than workshop A. How many tons of flour were originally planned to be processed?

Application Question 2

(1) There are two baskets of fruits. The weight of the fruits in basket A is 32 kilograms. After taking out 20% of the fruits from basket B, the weight ratio of the two baskets of fruits is 4: 3. How many kilograms did the two baskets of fruit weigh?

(2) It is planned to install 120 TV sets. If 8 sets are installed every day, the task can be completed one day ahead of schedule. If it is completed 4 days ahead of schedule, how many sets should be installed every day?

(3) Places A and B are 1152 kilometers apart. A passenger car and a freight train leave from both places at the same time. The freight train travels 72 kilometers per hour, which is 2/7 faster than the passenger car. How many hours will it take for the two vehicles to pass by? Encounter?

(4) The school buys a number of books and distributes them to each class. If each class is given 25 books, there will be 22 more books. If each class is given 30 books, it will be 68 fewer books. How many books are there? class? How many books did you buy?

(5) The fruit company stores a batch of apples. After selling 30% of the batch of apples, another 160 boxes are shipped. This is 1/10 more than the original apples stored. How many apples are there at this time? box?

(6) The greening team spent 900 yuan to renovate the street garden, saving 300 yuan compared with the original plan. What percent was saved? lt;/Plt; pgt;

(7) A road construction team built a road. The original plan was to build 200 meters a day, but actually built an extra 50 meters a day. As a result, the task was completed 3 days ahead of schedule. The entire road was How many meters long?

(8) There is a rectangular steel ingot with a base circumference of 2 meters. The ratio of length to width is 4:1. The height is 25% less than the width. It can be cast into a cone with a height of 3 decimeters. What is the base area of ??the cone?

(9) A wire uses 37.5% of its total length for the first time and 27 meters for the second time. At this time, the used wire is no longer used. The wire length ratio is 3:2. How many meters long was this wire?

(10) The number of boys in a certain class is 6 more than 5/7 of the class, and the number of girls is 4 less than 1/4 of the class. How many people are there in the class***?

(11) Warehouse A originally had 50 tons less grain than warehouse B. After transporting 30 tons of grain from warehouse A to warehouse B, the grain stored in warehouse A is 1/4 less than that in warehouse B. How many tons of grain are stored in warehouse B now?

(12) Put diesel into a cylindrical oil drum. It is known that the bottom diameter of the oil drum is 6 decimeters and the height is 10 decimeters. When full, the barrel weighs 280 kilograms. It is known that one liter of diesel weighs 0.85 kilograms. How many kilograms does the barrel weigh?

(13) A store purchased a batch of pens for 10.9 yuan each and sold them for 14 yuan each. When 4/5 of this batch of pens were sold, not only the entire cost was recovered, but also a profit of 150 yuan was made. How many pens are there in this batch?

(14) To process a batch of parts, the master can process 54 parts per day. If the apprentice processes it alone, it can be completed in 17 days.

Now two people are working at the same time. When the task is completed, the ratio of the number of parts processed by the master and the apprentice is 9:8. How many parts are there in this batch?

(15) Originally 1/5 of the students in Class 6 (1) participated in labor, and later two more students took the initiative to participate. In this way, the actual number of participants was 1/3 of the rest. How many people are there?

(16) There are ***100 big and small balls. 1/3 of the big ball is 16 more than 1/10 of the small ball. How many big and small balls are there?

(17) Mom bought 3 kilograms of bananas and 2 kilograms of pears and paid 13 yuan. It is known that the unit price of pears is 2/3 of bananas. How much is the price of pears per kilogram?

(18) The master and the apprentice made a batch of parts at the same time. The original plan was that the ratio of the number of parts made by the master and the apprentice was 9:7. When the task was completed, the master made 5 of the total. /8, 30 more parts were made than originally planned. How many parts did the master originally plan to make?

(19) There are 80 candies in a box of candy and they are divided between two brothers. The elder brother eats 1/3 of his, the younger brother eats 10, and then 5 more, leaving the rest The two brothers are exactly equal. How many grains did each brother get? lt;/Plt; pgt;

(20) There are two ropes A and B. Rope A is 35 meters longer than rope B. It is known that 1/9 of rope A is equal to 1/4 of rope B. Two ropes How many meters long are the ropes?

Application Question 3

(1) The circumference of the base of a cylinder is 2/3 of the circumference of the base of another cone, and the height of this cone is 2/5 of the height of the cylinder , what fraction of the volume of the cone is the volume of the cylinder?

(2) There is a cylindrical/glass cup. The inner diameter is measured to be 8 cm. The depth of the potion inside is 6 cm, which is exactly 4/5 of the content of the cup. How much potion should be added? , can you fill the cup?

(3) There are two baskets of apples. Basket A has 31 fewer apples than basket B. If 7 apples are taken from basket A and put into basket B, then the ratio of the number of apples in basket A and basket B is 4 :7. How many apples are there in basket B now?

(4) A, B and C produce a batch of parts together. The parts produced by A are 1/2 of the total number of parts produced by B and C. The ratio of the total number of parts produced by A and C to the number of parts produced by B It is 7:2. C produces 200 parts. How many parts does A produce?

(5) It takes a master worker 5 minutes to make a part, and his apprentice takes 9 minutes to make a part. After the master and apprentice worked together for a period of time, they made 84 parts in one day. How many parts did each of them make?

(6) A right-angled trapezoid, the ratio of the upper base to the lower base is 5:2. If the upper base is extended by 2 meters and the lower base is extended by 8 meters, it becomes a square. Find the area of ??the original trapezoid?

(7) The ratio of the number of people in teams A and B is 7:8. If 30 people are sent from team A to team B, then the ratio of the number of people in teams A and B is 2:3. How many people do teams A and B actually have?

(8) A truck transports goods from the county town to the mountains. It takes 20 hours to go back and forth to ***. The time taken to go is 1.5 times that of the return. It is known that the hour to go is longer than the return time. If the speed is 12 kilometers, find the round trip distance.

(9) If a project is completed by two construction teams A and B, it will take 12 days to complete. It is known that the work efficiency ratio of the two construction teams A and B is 2:3. This project will be completed by Team B. How many days will it take to complete it alone?

(10) A pile of coal, 1/4 of it is transported for the first time, and 120 tons are transported for the second time. At this time, the ratio of the tonnage of the remaining coal to the tonnage transported It's 2/3. How many tons did this pile of coal originally weigh?

(11) Two cars A and B are traveling towards each other from two places at the same time. They meet each other in 6 hours. When they meet, car A has traveled 72 kilometers further than car B. The speed ratio of car A and B is known. is 3:2, find the distance between the two places.

(12) Distribute a batch of chemical fertilizers to three villages, A, B, and C. Village A will get 1/4 of the total, and the rest will be divided between villages B and C at a ratio of 2:3. It is known that village C will get the fertilizer. 12 tons.

How many tons is this batch of fertilizer?

(13) A batch of goods was transported to two teams A and B according to the ratio of 5:7. Team B transported 840 tons, completing 4/5 of the task of the team. Later, it was transferred due to other tasks. After being transported by Team A, how many tons did Team A actually transport?

(14) There are 210 people in teams A and B. If 1/10 of the people from team B are transferred to team A, then the ratio of the number of people in teams A and B is now 4:3. Team A’s original number How many people?

(15) Three workers A, B and C made a batch of parts at the same time. A processed 2/5 of the total number, 125 more than B. The ratio of the number of parts processed by B and C is 3: 2. How many parts are there in this batch?

(16) The ratio of the speed of the truck to the speed of the passenger car is 3:4. The two trucks are traveling opposite each other from station A and station B at the same time, and meet 6 kilometers away from the midpoint. When the passenger bus arrives at station A, the truck leaves How far is station B?

(17) Shanhu Township transported a batch of pesticides, and 4/7 of the total was used on the first day, which was 12 kilograms more than twice the amount used on the second day. The ratio of the remaining pesticides is 27:8. How many kilograms does this batch of pesticides weigh?