1. The fertilizer plant produces an average of 250 tons of fertilizer every day in the first three days of the week, and produces 1 126 tons in the last four days. How many tons of chemical fertilizer does it produce every day this week?

2. On the first day, the canal was built for 3 hours, with an average of 4.5 kilometers per hour; The next day, it was repaired for 5 hours, averaging 5.3 kilometers per hour. How many kilometers have been built every day these two days? How many kilometers are repaired per hour on average?

3. Three groups collect tree species. The first group has 10 people and collects 180 kg of tree species every day. The second group 12 people, collecting 240 kilograms of tree species a day; The third group 13 people, collecting 280 kilograms of tree species every day. How many kilograms of tree species does each person collect on average?

4. The average score of the first three math exams in Zhang Hong is 92, and the fourth one is 96. What is his average score of four times?

5. The following is a statistical table of the donations made by Class 1 (1) of the Fifth Squadron of a primary school to the disaster area. Would you please calculate the average donation per person?

Donation amount (RMB) 3 5 8 10

Number 1 4 3 4

6. Xinghua Primary School has three classes in Grade Four. 1 class and class 2 have an average of 55 students, class 2 and class 3 have an average of 56 students, and 1 class and class 3 have an average of 52 students. How many students are there in each of these three classes?

7. 15 students were assigned comic books, with an average of 7 books per person. Later, several students came, and everyone redistributed them, with an average of 5 copies per person. How many students have come?

8. The distance between Party A and Party B is 16 1 km. It takes 3 hours for the bus to go from A to B, and it takes 1 hour to return from B. What is the average speed of the bus to and from A and B?

9. The average age of father and mother is 36.5 years old, and the age of son is 1 1 year old. What is the average age of the three of them after three years?

The average of 10 and nine numbers is 72. After removing one number, the average of the remaining numbers is 78. What is the number removed?

1 1, the average score of Chinese, foreign languages, ideology, morality and nature in the final exam in Han Lei is 8 1. After his math scores were announced, his average score increased by 2 points. What's his math score?

/kloc-Five students from Grade 0/2 and Grade 5 participated in the composition contest, and the average score of the four of them was 65. After adding Li Ming's score, the average score is 70. How many points did Li Ming get?

13 in the final exam, the average score of five subjects is 89, that of two subjects is 9 1 point, that of two subjects is 84, and that of two subjects is 86. English is more than Chinese1point. Ask Li Hua what is the score of these five subjects?

14. There are 7 numbers with an average of 32, the average of the first 4 numbers is 29, and the average of the last 4 numbers is 33. What's the fourth number?

15. Five judges scored a gymnast, and the average score was 9 points excluding the highest score and the lowest score. 58 points; If only one highest score is removed, the average score is 9. 46 points; Remove a minimum score alone, with an average score of 9. 66 points. What are the highest and lowest scores?

16. There are four barrels of gasoline. Take three barrels at a time, calculate their average, and add the weight of the other barrel. Calculated four times by this method, four kilograms were obtained respectively: 86,92, 100, 106. What was the average weight of four barrels of gasoline?

17. There are five numbers. Take four at a time, calculate the average and add another number. This method was used five times, and the following five numbers were obtained respectively: 24, 27, 29, 32, 38. Find the smallest of the first five numbers?

18. The average score of a student in politics, Chinese, mathematics, English and common sense is 89. The average score of political mathematics is 9 1. 5 points; The average score of Chinese and English is 84; The average score of politics and English is 85, and English is more than Chinese 10. How did the student do in five subjects?

19. One group has 12 students. Xiaojun called in sick during a math exam. 1 1 The average score of students is 85, and the make-up test score of Xiaojun is 5 points higher than that of 12 students. Five points. Q, how many points did Xiaojun get in the exam?

20. Xiaohua left home to go to school in the county. After walking at a speed of 50 meters per minute for 2 minutes, he found that if he walked at this speed, he would be 8 minutes later than originally planned, so he stepped up and walked 10 meters per minute. As a result, he still got 5 points in the school exam. Q: What is the distance between Xiaohua's home and school?

2 1. At 8 o'clock in the morning, a car drove from A to B, and the first hour was 40 kilometers. At this speed, it was 1 hour later than the original plan, so I drove at 50 kilometers per hour, and the result was 1 hour earlier than the original plan. Q: How long was the car originally planned to take?

22. Middle school student A walks from school to 20 at a speed of 4 kilometers per hour. It is 4 kilometers away from the military training ground. Half an hour later, an officer sets out from the military training ground to meet A, and the officer walks every hour 1 A. 2 kilometers, passing 1. Five hours later, middle school student B rode his bike from school to the military training ground. As a result, three people happened to meet at the same time on the road. What is the cycling speed of middle school student B?

23. Party A, Party B, Party C and Party D make paper flowers, while Party A, Party B and Party C each make 24 flowers on average, while Party B, Party C and Ding Pingjun each make 26 flowers. As we all know, Ding made 28 flowers. How many flowers did the Qiu family make?

24. There are three figures. The average of a and b is 2 1.5, the average of b and c is 22.5, and the average of a and c is 16. What are these three numbers?

25. Eight students from a school took part in a math contest, with an average score of 87.5, among which classmate A got 86. If classmate A only got 74 points, how many points did their average score drop?

26. Seven natural numbers are arranged in a row in descending order, and their average is 46. Suppose the first three numbers are 30, and the average value of the last five numbers is 54, then what is the third number?

27. The distance between Party A and Party B is 180km. When the car travels from A to B, it travels 45 kilometers per hour. When I returned to Party A from Party B, I traveled an average of 36 kilometers per hour due to many uphill roads. Ask this car how many times per hour on average.

28. The income of two vegetable fields * * * 14000 yuan, and the average income per hectare 1750 yuan. It is known that the income of the first vegetable field is 2500 yuan per hectare, which is 1000 yuan more than that of the second vegetable field. How many hectares are there in each of these two vegetable fields?