1, a bag of noodles, the first time I used it, it weighed exactly 4 kg, and the second time I used 1/4. How many kilograms are left?

A factory plans to produce a batch of parts. The first time 1/2, the second time 3/7, and the third time 450 parts were completed, and the result exceeded the planned 1/4. How many parts are planned to be produced?

Master Zhang finished a batch of parts in four days. On the first day,

54 were built the next day, and 90 were built on the second, third and fourth days. It is known that the quantity made the next day accounts for 1/5 of this batch of parts. How many parts are there in this batch?

4. Half of the boys in Class 6 (2) and 1/4 * * 16 girls, half of the girls and 1/4 * * 14 boys. How many students are there in Class Six (2)?

5. Party A, Party B, Party C and Party D have planted 600 trees. The number of trees in A species is 1/2, B species is 1/3, C species is 1/4 and D species is 1/4.

6.5 (2) Class originally planned to allocate 1/5 people to participate in cultural and entertainment performances, and 2 people participated temporarily, so that the actual number of participants was the rest 1/3. How many people were originally planned to attend the cultural and entertainment performance?

7. The three workshops of the toy factory make a batch of toys together. The first workshop made 2/7 of the total, the second workshop made 1600, and the third workshop made half of the sum of the first and second workshops. How many toys are there in this batch? (two solutions)

8. There are five consecutive even numbers. It is known that the third number is more than the sum of the first number and the fifth number 1/4. What is the sum of these five even numbers?

9. There are 54 people in Group A and Group B. The number of people in Group A is 1/4, which is equal to the number of people in Group B. How many people are there in Group A than in Group B?

10, and the circumference of the rectangle is 130 cm. If the length increases by 2/7 and the width decreases by 1/3, the circumference of the new rectangle will remain unchanged. Find the length and width of the original rectangle.

1 1. There are 5400 original literature and art books and science and technology books in the school library, among which science and technology books are less than literature and art books 1/5. I bought a batch of science and technology books recently. At this time, the ratio of science and technology books to literature and art books is 9: 10. How many science and technology books did the library buy?

12. The initial capital ratio between Party A and Party B is 3︰4. Later, Party A gave 50 yuan to Party B, and Party A's money was 65438+ 0/2 of Party B's. How much did A and B have?

13, the price ratio of a and b is 7︰3. If their prices rise by 70 yuan respectively, then their price ratio is 7︰4. What is the original price of commodity A?

14. The sum of the numerator and denominator of the simplest fraction is 49 people. After the numerator adds 4 and the denominator subtracts 4, the new score can be reduced to 3/4, and the original `score?

15, Party A and Party B each saved a few yuan. After the deposit paid by Party A to Party B 1/5, Party B pays the existing deposit to Party A 1/4. At this time, they all have 180 yuan. How much did each of them save?

16. There is a peach tree on the hill. A monkey went to steal peaches. On the first day, he stole110, and in the next eight days, he stole 1/9, 1/8 and 1/7 of existing peaches respectively. How many peaches are there on the tree?

17, a bunch of watermelons, 1/4 and 4 of the total amount sold for the first time, the remaining 1/2 and 2 for the second time, and the remaining 1/2 and 2 for the third time, leaving 2. How many watermelons are there in this pile?

18, Xiao Ming reads a book. On the first day, he finished reading 1/8 of this book in 16 pages. The next day, he read 1/6 of the book, and two pages were missing, leaving 88 pages. How many pages are there in this book?

In the first experiment, * * *, there were 19 students in grade five, and11boys and 5 girls participated in the science and technology group, and the rest were just equal. How many boys and girls are there in Grade Five?

20. Class A and Class B * * total 162 people. The number of participants in Class A is less than that in Class B 1/5, and Class B is less 1/4. How many people from Class A and Class B participate in the activities of the Science and Technology Group?

Special training on the application of Olympic mathematics in the sixth grade of primary school (2)

1. The engineering team plans to repair a 4800-meter-long road with 60 people in five days. In fact, 20 people were added, and each person repaired 4 meters more than planned every day. How many days did it actually take to complete this road?

2. (encounter problems) Two cars A and B start from east and west at the same time. Car A travels 56 kilometers per hour and car B travels 48 kilometers per hour. The two cars met at a distance of 40 kilometers from the midpoint. How many kilometers are there between things?

The bus and the car leave in the same place and the same direction. The bus travels 60 kilometers per hour and the car travels 84 kilometers per hour. The bus did not leave until two hours after the bus left. How many hours will the bus catch up with?

4. (Crossing the Bridge) The train crosses a 2700-meter-long bridge. It takes 3 minutes to get on the bridge from the front and get off the bridge from the back. The known train speed is 1000 meters per minute. How long is the train body?

5. (Wrong train problem) The passenger train conductor is 280 meters long and the freight train conductor is 200 meters long. They walk opposite each other on parallel tracks, and it takes 20 seconds from the time when two cars meet to the time when the next car leaves. If two cars are driving in the same direction, with the truck in front and the bus behind, the time from the moment when the front of the bus meets the rear of the truck to the moment when the rear of the bus leaves the front of the truck is 120 seconds. What are the speeds of the bus and the truck respectively?

6. (Navigation) Passenger ships and cargo ships leave from Port A and Port B at the same time. Six hours later, the passenger ship and the cargo ship met, but there were still six kilometers from the midpoint of the two ports. It is known that the speed of passenger ships in still water is 30 kilometers per hour, and that of cargo ships in still water is 24 kilometers per hour. What is the current speed?

7. Xiao Li has 30 stamps and Xiao Liu has 15 stamps. How many stamps did Xiao Liu give Xiao Li, and the number of stamps of Xiao Li is eight times that of Xiao Liu?

8. The students donated money for Project Hope. The donation in grade six is three times that in grade two. If 160 yuan is put into the second grade from the donation of the sixth grade, then the donation of the sixth grade is 40 yuan more than that of the second grade. How much do the two grades donate respectively?

9. (Sum and Difference Problem) A two-story bookshelf can hold 72 books. If you take out nine books from the upper level to the lower level, the upper level has four more books than the lower level. How many books are there on each floor?

10. (Periodic problem) July 2006 1 is Saturday. What day is today?

1 1. (Chickens and rabbits in the same cage) Xiaoli bought 50 exercise books from 0.8 yuan and 0.4 yuan respectively and paid RMB 32 yuan. How many exercise books are there in 0.8 yuan?

12. Five years ago, my father was seven times older than my son. After 15, the father is twice as old as his son. How old are my father and son this year?

13. (profit and loss problem) Teacher Wang distributed notebooks to students, with 6 copies for each student, leaving 4 1 book, with 8 copies and 29 copies for each student. How many students are there? How many notebooks are there?

14. (Reduction problem) Convenience fruit shops sell mangoes. For the first time, they sell more than half of the total mangoes, for the second time, they sell more than half with 1, and for the third time, they sell less than half with 1. At this time, only 1 1 mango is left. How many mangoes are there in the fruit shop?

15. The school bought 6 tables and 6 chairs, and spent 192 yuan. As we all know, the price of three tables is equal to the price of five chairs. How much is each table and chair?

16. (Best arrangement) Only two loaves can be baked on the baking rack at a time, and it takes 2 minutes to bake one loaf on each side. How many minutes does it take to bake three loaves of bread?

17. (Oil drum problem) Weight of a barrel of oil 18kg. After removing half of the oil, the barrel weighs 9.75 kilograms. How many kilograms is the original oil? How much does this bucket weigh?

⑻ Qingqing Farm has * * * chickens, ducks and geese *** 12 100. There are twice as many ducks as chickens, and four times as many geese as ducks. How many chickens, ducks and geese are there?

19. The experimental primary school held a math contest. Every time you do a right question, you get 9 points, and if you do a wrong question, you get 3 points. * * * There are 12 questions, and Xiao Wang scored 84 points. How many questions did Xiao Wang do wrong?

20. (Meeting problem) A and B walk in opposite directions from two places 2000 meters apart at the same time. A walks 55 meters per minute, and B walks 45 meters per minute. If the dog and A walk in the same direction at the same time, walk120m per minute. Immediately after meeting B, turn back and run to A, then run to B. How many meters did the dog walk before meeting A and B?

fill (up) a vacancy

1. The simplest true fraction in which the product of numerator and denominator equals 420 is _ _ _ _ _. The third score from the largest to the smallest is _ _ _ _ _ _ _ _ _.

2. There are 88 pears and apples, one pear in 0.5 yuan and one apple in 0.7 yuan. It takes 13 pears and 14 apples 15 yuan, and it takes _ _ _ _ _ _ yuan to buy all pears and apples.

3. In 2005, students formed a row, the first time from left to right 1 ~ 3, and the second time from right to left 1 ~ 5. A student whose sum of two reports is equal to 5 is famous.

4. New Century Bilingual Schools 1200.

Students, each student has five classes a day and each teacher has four classes a day. There are 30 students and one teacher in each class. There are * * * teachers in this school.

Because A runs faster than B, either A retreats 30 meters from the starting point or B advances 25 meters from the starting point, both of which can start at the same time and reach the finish line at the same time. Q: How many times faster is A than B?

6. When doing a two-digit multiplication problem, Xiao Mahu regards the number 5 in a multiplier as 8, and the product is 1872. Then the original product is _ _ _ _ _ _ _ _.

7. The combined age of mother and daughter this year is 88. When the mother is the same age as her daughter this year, the mother is exactly four times as old as her daughter. Q: My daughter is _ _ _ _ _ _ _ _ years old this year.

Second, answer questions:

8. The selling price (marked price) and buying price of all the same goods in two electrical stores A and B are the same. Lao Wang bought a refrigerator and a microwave oven in shop A, with a 20% discount. Lao Li bought an identical refrigerator from store B and got an identical microwave oven. Shop A sold Lao Wang a refrigerator and a microwave oven, which won 460 yuan. Shop B sold Lao Li a refrigerator, but the actual gross profit was 550 yuan. Knowing that the price of microwave oven was refrigerator, he asked the price of refrigerator.

9. Xiaoming ran a circle on the 360-meter-long circular runway. He ran 5 meters per second in the first half and 4 meters per second in the second half. How many seconds did it take him to finish the second half?

10. There are four scientists, A, B, C and D. The result of adding their ages is 99 years old, 1 13 years old, 125 years old, 130 years old, 144 years old.

1 1. The pure alcohol content of alcohol A is 72%, the pure alcohol content of alcohol B is 58%, and the mixed pure alcohol content is 62%. If the amount of each alcohol is more than the original 15 liter, the pure alcohol content after mixing is 63.25%. Please take alcohol A and alcohol B at the same time when mixing for the first time.