1. In a mountaineering activity, Zi Han climbed 50 meters every minute and reached the top of the mountain in 18 minutes. Then go down the mountain along the original road and walk 75 meters per minute. How many meters does Zi Han walk up and down the mountain every minute?

2. In the fourth grade, 60 students went to plant trees, with an average of 4 trees per person, just after planting. Later, some students were sent. At this time, everyone can plant three trees on average to complete the task. How many students were sent?

3. Several students calculate the average score of their Chinese exam together. If Zi Han's score increases by 13, their average score will reach 90, and if Zi Han's score decreases by 5, their average score will be only 87. How many students are there?

4. A student from Jiuhu Central Primary School participated in the math contest, with an average score of 63, including 60 for boys and 70 for girls. How many boys and girls are there?

5. The average of A and B is 26, that of B and C is 28, and that of A and C is 2 1. Find the average of a, b and c.

6. Zi Han took part in the sports standard test, and the average score of five events was 85. If the throwing score is not included, the average score is 83 points. How many points did Zi Han score in throwing?

7. If the average age of four people is 23, and no one is younger than 18, how old is the oldest person?

8. The average of five numbers is 45. Arrange these five numbers from small to large. The average of the first three numbers is 39, and the average of the last three numbers is 53. What is the third number?

9. Zi Han participated in three math competitions, with an average score of 84. It is known that the average score of the first two competitions is 82 points. How many points did he score in three competitions?

10. In the final exam, Zi Han's average score in four subjects was 92 before the math scores were announced, but after the math scores were announced, his average score dropped by 1. How many points did Zi Han get in the math exam?

1 1. If the average age of three people is 22 years old, and no one is younger than 18 years old, what is the oldest person?

12 ... If the average age of four people is 25 years old, and no one is younger than 16 years old, and these four people are not equal in age, how old is the oldest person? How old is the youngest person?

13. In a mountaineering activity, Zi Han walked up the mountain 50 meters per minute, and then walked down the mountain 75 meters per minute according to the original road. How many meters does Zi Han walk up and down the mountain every minute?

14. A classmate read a story book, reading 25 pages every day for the first 4 days, then reading 40 pages every day for 6 days. How many pages does the student read on average every day?

15. Zi Han reads a story book, reading 25 pages every day for the first 4 days, and finishing these pages in the next 6 days. How many pages does the student read on average every day?

16. Han Qi got an average of 96 points (full marks) in five exams, so how many points should she get in each exam?

Fourth grade application questions 1

1, Grandma went to fruit, and she spent 4 Jin of pears and 5 Jin of litchi in 68 yuan. 1 kg pear and 3 kg litchi are the same price. How much is 1 kg pear and 1 kg litchi?

3 baskets of apples and 5 baskets of oranges weigh * * * kg. The weight of each basket of apples is twice that of each basket of oranges. How much does each basket of apples and oranges weigh?

Teacher Zhang is reading in the reading room. He bought six fairy tale books and seven story books with RMB, and the prices of three fairy tale books and five story books were the same. 1 How much is the fairy tale book and 1 story book?

4. A batch of grain was shipped out from the grain depot. Four bags of rice and five bags of flour weigh * * * kg, and four bags of rice and seven bags of flour weigh * * * kg. How many kilograms does each bag of rice and flour weigh?

1, standard oil drum, oil * * * weighs 7kg. Uncle Ma, the driver, has used half of the oil, and now the barrel weighs 4 kilograms. How many kilograms of oil are there in the barrel? How many kilograms of oil is there in this barrel of oil? How much does this bucket weigh?

A bottle of perfume weighs 50 grams. The perfume is half used and the bottle weighs 30 grams. How many grams of perfume are there? How many grams does this bottle weigh?

A bottle of wine weighs 80 grams. After drinking half the wine, the bottle weighs 50 grams. How many grams of wine are there? How many grams does this bottle weigh?

A bottle of soda weighs 45g. After using half the soda, the bottle weighs 25 grams. How many grams of soda are there? How many grams does this bottle weigh?

1, there are 6 boxes of eggs, and each box has the same number of eggs. If you take out 50 eggs from each box, the number of eggs in the remaining six boxes is exactly the same as that in the original five boxes. How many eggs are there in each box?

There are 7 baskets of apples, and the number of apples in each basket is equal. If you take out 40 apples in each basket, the number of apples in the remaining seven baskets is exactly the same as that in the original five baskets. How many apples are there in each basket?

3. 5 boxes of biscuits, each box of eggs has the same weight. If you take out 40 grams from each box, the total grams left in the five boxes are exactly the same as those in the original three boxes. How many grams of biscuits are there in each box?

There are 6 classes in Senior One, and the number of students in each class is equal. If there are 30 students in each class, the number of students left in class 6 is exactly the same as that in class 2. How many students are there in each class?

1, Han Qi practices calligraphy and plans to write every day. In fact, she wrote four more words than planned every day, and she finished the task one day ahead of schedule. How many words are you going to write?

2. Zhang Zihan has read a book and plans to read 15 pages a day. In fact, he reads three pages more than planned every day. As a result, he finishes the task two days ahead of schedule. How many pages are there in this book?

3. Road construction, originally planned to build 60 meters a day, actually built 8 meters more than planned every day. As a result, the task was completed four days ahead of schedule. How long is this road?

4. Michael Chen plans to do 30 paper crane projects every day, but in fact, it does 6 more projects every day than planned. As a result, the task was completed three days ahead of schedule. How many paper cranes do you plan to make?

1, Han Qi has 10 pictures, and Zheng Jie has 4 pictures. How many photos did Han Qi give Zheng Jie? How many photos do they have?

There are 52 glass balls in the red box and 34 glass balls in the blue box. Take three out of more boxes and put them into fewer boxes at a time. How many times does it take to make the number of glass balls in two boxes equal?

There are 68 sweets in the big bag and 28 sweets in the small bag. How many times have you taken four pieces from many bags and put them in several bags?

There are 25 books on the upper shelf, 27 books on the lower shelf, and 10 books returned by my father. How can I put it so that there are as many books on the upper and lower shelves?

Fourth grade application problem 2

1. The TV factory installs a batch of TVs, 80 of which are installed every day. /kloc-The task can be completed in 0/5 days. How many TVs will be installed every day if it is to be completed three days in advance?

A factory saves 40 kilograms of coal every day. If every 8 kilograms of coal can generate electricity 16 kwh, according to this calculation, how many kwh of coal can be saved by the factory in September (calculated in 25 days)?

3. A workshop plans 20 people to work 8 hours a day, complete a batch of orders in 8 days, and then deliver the goods in advance. The goods will be completed by 32 people in 4 days. How many hours do you have to work every day?

4. Teacher Zhang from the general affairs office of the school went to the store to buy exercise books for the students. The exercise book was priced at 80 cents in 4 yuan and left with the money. Because it's much more, yes, it's 30 cents cheaper. How many exercise books does Teacher Zhang return?

An engineering team is expected to use 20 people to dig a canal in 14. Digging for two days, plus 20 people, everyone's work efficiency is the same. Can you finish it a few days in advance?

6. The boiler reserves the heating coal for days according to the daily consumption of kilograms. After heating for 40 days, due to technical transformation, coal kilograms can be saved every day. How many days can these coals be heated?

7. The school canteen goes to the farmer's farm to lay eggs. 5 yuan laid eggs at a rate of 96 kg per kg. As a result, the price of eggs was lowered, and 24 Jin of eggs were added with this money. How much is the egg per kilogram after the price is lowered?

8. 18 people took part in the labor of moving brick piles, which is planned to be completed in 8 hours. After two hours of actual labor, six people were transferred. How many hours does it take to move the remaining bricks?

9. Twenty-four trucks can transport goods at the same time. Now, there are six more trucks that are the same. How many goods can they ship at a time?

10, Zhang plans to process parts. Five parts were processed in the first five days. According to this calculation, how many days will it take to process this batch of parts?

1 1, 3 The mill can process wheat kilograms in 4 hours. According to this calculation, how many kilograms of wheat can five mills process in six hours?

12, four machine tools in a machinery factory can produce parts in five hours. According to this calculation, how many hours does it take to add six identical machine tools to produce a part?

13, a road construction team plans to build rice. It was originally planned to arrange seven workers to finish it in six days. Later, the task of 54 meters was added, which required 6 days to complete. If every worker has a certain amount of work every day, how many workers will be needed to finish the work on time?

14, Jiuhu Central Primary School bought a batch of chalk. It was originally planned that 25 classes could take 40 days. It actually took 10 days, and 10 class was out. How many days is there left of chalk for school?

15, Yangdong Power Plant has coal. It burned coal every day for more than ten days, and then improved the stove and burned coal every day. How many days can this pile of coal burn?

16, and the apprentice began to process all parts at the same time, processing 25 pieces per hour. When I finished the task, my apprentice had to work for 2 hours to finish the task. How many do apprentices process per hour?

17. The distance between Party A and Party B is1000m. It takes 5 hours by car and 40 hours on foot. Mr. Zech starts from A and takes the bus after 8 hours' walk. How many hours does it take to get to B?

18, Xu Ting Road Construction Team built a long road. It was originally planned to build 4 meters per person per day, and 2 1 person was sent to complete it. Four people were added during the actual construction, so how many days can the task be completed in advance?

19, Shu Kei Bicycle Factory plans to produce bicycles every day, and can finish the task on schedule. In fact, it produces a car every day and finishes the task eight days ahead of schedule. How many bicycles are there in this batch?

Todd planned to finish some calculation problems in 30 days, but in fact, he calculated 80 more problems every day than originally planned. As a result, the task was completed in 25 days. How many problems are there in these calculations?

Fourth grade sum and difference problem

1. 1. There are 50 volleyball and football in the school, four more than football. How many volleyball and football are there?

2. There are workers in both workshops A and B. Workshop A has 30 fewer workers than workshop B. How many workers are there in workshops A and B?

3. Two engineering teams, Party A and Party B, jointly dug a canal with a length of 48km. Team A dug 6 kilometers more than Team B. How many kilometers did each team dig?

Xiao Ning and Xiao Fang are both 28 years old this year. Xiao Ning is two years younger than Xiao Fang. How old is Xiao Fang this year?

The average age of Xiao Min and his father is 29, and his father is 26 years older than him. How old are Xiao Min and his father?

6. In Xiaolan's final exam, the average score of Chinese and mathematics was 96, and mathematics was 4 points more than Chinese. How many points did Xiaolan get in Chinese and Mathematics?

2. 1, A and B have books. If you take out 40 books from shelf A and put them on shelf B, the number of books on the two shelves is exactly the same. How many books are there on the shelves A and B?

There are 30 kilograms of water in two buckets. If you pour 6 kilograms of water from the first bucket into the second bucket, there is as much water in the two buckets. How many kilograms of water are there in each bucket?

3. warehouses a and b store 58 grains of rice. If three rice are transferred from warehouse A to warehouse B, the two warehouses store exactly the same amount of rice. How much rice do warehouses A and B store?

4. Party A and Party B each have RMB * * *. If Party A increases RMB 65,438+03, and Party B decreases 27 yuan, the amounts of both parties are equal. How many are A and B?

3. 1, two piles of goods A and B * * *, and the shipment of pile A is 30 or 12 is more than that of pile B. How much are those two piles?

There are two piles of goods. If 30 piles of goods are transported from pile A to pile B, the goods in pile A are still more than those in pile B 10. What are the two piles of goods?

3. The apples in Basket A and Basket B are both * * * kilograms. Take out 5 kilograms from Basket A and put them in Basket B. As a result, the apples in Basket A are 2 kilograms less than those in Basket B ... How many kilograms of apples are there in Basket A and Basket B?

4. Both schools have students. If school A transfers 20 students and school B transfers 15 students, school A has 5 more students than school B.. How many students are there in each school?

There are three kinds of vegetables in the school canteen, among which cucumbers and tomatoes weigh 50 kilograms, vegetables and cucumbers weigh 70 kilograms and vegetables and tomatoes weigh 60 kilograms. How many kilograms are there in each of these three vegetables?

6. A Dream of Red Mansions is divided into upper, middle and lower volumes, with a total volume of RMB * * *. The first volume is more expensive 1 1 yuan than the middle volume, and the second volume is cheaper than the middle volume, 5 yuan. How much are the first, middle and second volumes?

7. The sum of four people's ages is 77 years old, and the youngest is 10 years old. The combined age of him and the oldest person is seven years older than the combined age of the other two. What's the oldest age?

8. Xiao Nuo ran five times along the swimming pool with a difference of 30 meters in length and width, doing preparatory activities before launching. As we all know, Xiao Nuo ran 100 meters. Q: What is the length and width of the swimming pool?

9. Ceng Laoshi weighs 30 kilograms more than Han Qi, Ceng Laoshi weighs 25 kilograms more than Chen He, Han Qi Chen He weighs 75 kilograms, and Han Qi Michael Chen each weighs how many kilograms?

10. There are many flower seedlings in the nursery. One is not a rose and the other is not a peony. There are two kinds of roses and peonies. How many roses and peonies are there?

Fourth grade and doubling problem

1, Xiaohong and her mother add up to 40 years old, and her mother is four times as old as Xiaohong. How old are Xiaohong and her mother?

2. The sum of numbers A and B is that the quotient of number A divided by number B is 4. What are the numbers A and B respectively?

The length of a rectangular board is twice the width, and the circumference is 54 cm. How big is this rectangular block of wood?

4. A basket of apples, a basket of pears and a basket of grapes weigh 42kg. I know that apples weigh twice as much as grapes, and pears weigh three times as much as grapes. How many kilograms are apples, pears and grapes?

5. Planting trees in three classes in grade three. The number of trees planted in Class Two is twice that of Class One. There are as many trees planted in Class Three as in Class Two. How many trees are there in three classes?

6. There are three piles of coal, and pile A is three times as big as pile B, pile C is twice as big as pile A, and the three piles of coal weigh * * * kilograms. So how many kilograms do pile A, pile B and pile C weigh respectively?

7. There are three road repair teams working together to build a road 1000 km long. Team a is three times as big as team b and team c is twice as big as team a, so how many kilometers will team a, team b and team c build?

Teacher Zhang returned 83 balls to basketball and football, of which basketball is twice as big as football. How many balls are there?

9. Teacher Zhang returned 83 balls to basketball, football and volleyball, of which basketball is twice as big as football and volleyball is twice as big as football. How many of these three kinds of balls are there?

10, Teacher Zhang returned 83 balls to basketball, football and volleyball, in which basketball is twice as big as football and football is five more than volleyball. How many of these three kinds of balls are there?

1 1, 30 for Xiaohua and 0/5 for Xiaoming. After asking Xiao Ming how many to give Xiaohua, Xiaohua's pen is 8 times that of Xiao Ming.

12, Xiaoming has 18, Xiaofang has 8, and now there are 16. How to distribute them so that Xiao Ming's books are twice as big as Xiao Fang's?

13. There is 60 water in Pool A and 30 water in Pool B. If the water in Pool A flows into Pool B at a rate of 3 per minute, how many minutes later will the water in Pool B be twice as much as that in Pool A?

14, a division formula, the quotient is 18, the remainder is 4, the sum of dividend, divisor, quotient and remainder is, what are the divisor and dividend respectively?

Differences in the fourth grade

1. Linxia primary school bought three times as much volleyball as basketball, and volleyball was more than basketball 18. How much are volleyball and basketball purchased separately? How many volleyball and basketball did you buy?

There are two bookshelves, the big one and the small one. There are four times as many books on the big shelf as on the small shelf. If you take out the books on the big shelf and put them on the small shelf, the number of books on the two shelves will be equal. How many books are there in each bookcase?

3. Old cats and kittens go fishing. This old cat catches three times as much as a kitten. If the old cat gives the kitten three, the kitten is two less than the old cat. How many fish do two cats catch?

Teacher Zhang reported that basketball has 83 more goals than football, among which basketball has 5 more goals than football. How many balls do these two kinds have?

5. The kilograms of white sugar in the grocery store are 35 kilograms less than those of brown sugar, and it is known that white sugar is 4 1 kg more than brown sugar. How many kilograms of white sugar and brown sugar are there in the grocery store?

6. Teacher Zhang returned to basketball, football and volleyball, in which football is three times as big as basketball, football is seven times more than volleyball, and volleyball is more than basketball 1 1. How many balls do these three kinds have?

7. Pears are kilograms heavier than grapes, apples are twice as heavy as grapes, and apples are heavier than pears. How many kilograms are apples, pears and grapes?

8. Xiaoming's deposit is three times that of Xiaogang. Now Xiaoming takes out RMB and Xiaogang takes out RMB, and their deposit amount becomes the same. How much did Xiaoming and Xiaogang save?

9. The amount of grain stored in warehouse A is three times that of warehouse B. If 60 grains are taken out of warehouse A and 80 grains are brought in from warehouse B, the amount of grain stored in two granaries A and B is exactly the same. How much are stored in granaries A and B respectively?

10, two granaries, A and B, each store a number of grains, and the quantity of grains stored in warehouse A is three times that of warehouse B. If 60 grains are imported from warehouse A and 60 grains are imported from warehouse B, then the quantities of grains stored in two granaries, A and B, are equal. How much are stored in granaries A and B respectively?

1 1. Xiao Zhang has 36 extra-curricular books and Xiao Xu has 24 extra-curricular books. After they donated the same number of books, Xiao Zhang left three times as many books as Xiao Xu. How many books did they each donate?

12, master and apprentice process the same batch of parts, one part is processed, and the apprentice processes 40 parts. At this time, the number of apprentices left behind was three times that of the original. How many parts do master and apprentice have to process?

Solve a problem with a hypothetical method

Number of rabbits = (total number of feet-number of feet per chicken × number of chickens and rabbits) ÷ (number of feet per rabbit-number of feet per chicken)

Number of chickens = total number of chickens and rabbits-number of rabbits (assuming chickens, find rabbits first)

Or: number of chickens = (number of feet per rabbit × total number of chickens and rabbits-total number of feet) ÷ (number of feet per rabbit-number of feet per chicken)

Number of rabbits = total number of chickens and rabbits-number of chickens (assuming rabbits, find chickens first)

1, 30 chickens and rabbits, 70 feet, how many chickens and rabbits are there?

There are 20 chickens and rabbits and 50 feet. How many chickens and rabbits are there?

3. In a parking lot, 48 cars and motorcycles were parked, including four wheels for each car and three wheels for each motorcycle. These cars have only one wheel. How many cars and motorcycles are there in the parking lot?

4. The PE teacher bought ***2 1 sportswear tops and pants, and * * spent RMB, including each coat in 24 yuan and each pair of pants 19 yuan, and asked the teacher how many coats and pants were there?

1, a and b tickets, a ticket for each 6 yuan, b ticket for each 4 yuan, two 1 1, a 50 yuan, how many tickets each?

2. In Yangdong, there are ***30 banknotes with face value from 2 yuan to 5 yuan, 1 banknote with face value from 90 yuan. How many bills are there from 2 yuan to 5 yuan?

3.2.5 cents 1 yuan is 20 dollars, * * is 12 yuan, so 1 yuan has _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

1, a batch of cement, packed by car, needs to be packed by 20 cars, as long as 12 cars, each car is loaded with 4 more cars than cars. How much is this batch of cement?

2, a pile of cement, with small trucks loading, with 30 cars, with big trucks loading, as long as 24 cars, each big truck loading five more than the small truck loading. How much is this batch of cement?

1. stipulates that the freight for a shirt box is 30 yuan per box. If you lose a box, you will not only pay the freight, but also compensate RMB. The freight after shipment is RMB. How many boxes were lost in this transportation?

In an English contest in a primary school, he got 10 for every question he answered correctly. If he didn't do or answer a wrong question, he got 2 points. * * * 15, Xiao Ming scored. How many questions did he answer correctly?

3. Jiuhu Primary School Sixth Grade Mathematics Competition, with ***20 questions. Get 5 points for answering a question correctly, and get 3 points for not doing a question or doing a wrong question. If you get 60 points, how many questions will he get right?

4. The worker transported a celadon vase, and agreed to transport the whole vase to the destination to pay the freight to 20 yuan, and compensate one for damage. After these vases were shipped, the workers got * * *, but how many were damaged?

1, Chris Lee concert sold * * * tickets to 30 yuan, 40 yuan and 50 yuan, earning RMB, among which 40 yuan and 50 yuan had equal tickets. How many tickets of each kind were sold?

2. Wang Shuqi sold * * tickets to 30 yuan, 40 yuan and 50 yuan and earned RMB, among which 40 yuan and 50 yuan had equal tickets. How many tickets of each kind were sold?

Spiders have eight legs, dragonflies have six legs and two pairs of wings, and cicadas have six legs and 1 pairs of wings. Now these three kinds of bugs have 16, * * * has a leg, and 14 pairs of wings. Q: How many insects are there in each species?

2. The prices of the three exercise books A, B and C are 7, 3 and 2 points respectively. I bought 47 exercise books of three kinds and paid 2 1 yuan 2 cents. The number of exercise books in the second category is twice that in the third category. How many exercise books did you buy each of these three?

3. Some 4-cent and 8-cent stamps are worth 80 cents in 6 yuan RMB. As we all know, there are 40 8-cent stamps more than 4-cent stamps, so how many did you get each?

4. There are *** 14 one-yuan, five-yuan and ten-yuan coins, and * * is counted as 66 yuan, among which one-yuan coins are 2 more than ten-yuan coins. How many coins are there in each of these three kinds of coins?

Relationship between profit and loss issues:

1, (surplus+deficit) ÷ Difference between two distributions = number of copies.

2. (big profit-small profit) ÷ Difference between two issues = number of copies

3, (big loss-small loss) ÷ Difference between two distributions = number of copies

Points per time × copies+surplus = total, points per time × copies-loss = total,

The key to solve the profit and loss problem problem is to find the total difference and quantity difference of two distributions, and then find the number of distributors and the number of goods by using the basic formula.

1. There are some toys in the kindergarten. If there are 8 toys in each class, there will be 2 more. If there are 10 toys in each class, there will be less 12 toys. How many classes are there in kindergarten? How many toys are there in this batch?

Xiaoming took some money to buy apples. If it is 3 kilograms, it will cost 2 yuan more. If it is 6 kilograms, it will cost 4 yuan less. How much are apples per kilogram? How much money did Xiaoming bring?

A group of people went to the hillside to plant trees. If everyone plants four trees, there are still 12 trees left. If each race has planted eight trees, there are still four trees missing. How many people are there in this group? How many trees are there?

A group of students are moving books. If each student moves two books, there will be 12 books left. If each student moves four books, six books are still missing. How many students are there in this group? How many books are there in this batch?

1. The teacher gave some excellent young pioneers exercise books. If you give five copies to everyone, there will be an extra 14 copies. If each person is divided into seven books, there will be two more; How many outstanding young pioneers are there? How many exercise books?

2. Give the children a bag of candy. If each child is divided into 4 pieces, there will be an extra 12 pieces. If each child is divided into six pieces, there will be two more pieces. How many children are there? How many sweets are there?

Mom gives some apples to the whole family. If everyone gets six apples, there will be 12 more apples. If everyone gets seven apples, there will be six apples. How many people are there in the family? How many apples did mom return?

4. Some students live in a school, each dormitory has 8 people, and there are 24 beds left. If each dormitory has 10 people, there are only two beds left. How many dormitories are there in the school? How many boarding students are there?

1. The school sent some students to move saplings. If everyone moves six trees, the difference is four. If each person moves eight trees, the difference is 18. How many students did the school send? How many saplings are there in this batch?

In science class, the teacher distributed leaves to the students. If each student is divided into five leaves, there are three leaves. If each student is divided into 7 leaves, there are 25 leaves. How many students are there in this class? How many leaves did the teacher bring?

3. Students in the math interest group do math problems. If each student does six questions, there are four less. If each student does 8 questions, it will be less 16. How many students are there? How many math problems are there?

4. School rehearsals. If there are 8 people in each row, there will be 2 people missing in that row. If there are 9 people in each row, then there are 7 people missing in one row. How many rows will there be in one row? A * * * How many people are there?

1 Class 3 (1) students go boating in the park. If there are four people on each boat, there will be four more. If each ship takes 6 people, there will be 4 more ships; How many boats are there in the park? How many students are there in Class Three (1)?

2. The school allocates dormitories to new students. If there are eight people in each room, there will be two fewer rooms. If there are 10 people in each room, there will be two more rooms. How many rooms will freshmen be assigned? How many freshmen are staying?

3. Students go boating. If there are five people in each boat, then 10 people have no boat. If there are two more people on each boat, there will be two more boats. How many ships are there? How many students are there?

Xiao Ming walks 40 meters every minute from home to school, which means he is 2 minutes late, and walks 50 meters every minute, which means he is 4 minutes early. How far is Xiaoming's home from school?

1, the exercise book for junior three students, if each student sends 5 copies, there are still 32 copies left, if each student of 10 sends 4 copies and the rest sends 8 copies, it is just finished. So how many students are there in grade three? How many exercise books are there?

2. Xiaoming wrote a book "Interesting Mathematics". He planned that if he did three questions every day, there would be 16 questions left. If he does five questions every day, he will only do 1 on the last day. So how many problems does this book have? How many days does Xiaoming plan to do it?

Students in Class 3 (2) go to plant trees. If they plant five trees each, there are still three left unattended. If four of them plant four trees and the rest plant six trees, all the trees will be planted. So how many students took part in the tree planting activities? How many trees have been planted?

Xiao Ming looked at his watch when he came home from school and found that if he walked 80 meters per minute, he would be 5 minutes late. If he had left 10 minutes earlier, he would have cycled to school 1 minute earlier. How many minutes did Xiao Ming leave home for school?