X=50 y=45 when solving a quadratic equation, that is, Lily 50 yuan's 45 yuan book 30 yuan.
2. A car consumes 4/5 kilograms of fuel per line for 8 kilometers, and how many kilometers per kilogram of gasoline is feasible on average. How many kilograms does driving 1 km consume? 8 divided by 4/5= 10 (km /) 4/5 divided by 8=0. 1 (kg)
3. A motorcycle 1/2 hours for 30 kilometers. How many kilometers does it travel per hour? How many hours does it take him to drive 1 km? 30 ÷1/2 = 60km1÷ 60 =1/60h.
Four out of seven students reading in the reading room are boys. After five male students walked out of the reading room, twelve of the twenty-three were female students. How many students were reading in the original reading room? There were x students, and the number of girls remained the same, so (1-4/7) x = (x-5) *12/23 found that x=28.
There are 62 red, yellow and blue balloons, of which three-fifths of the red balloons are equal to two-thirds of the yellow balloons, and there are 24 blue balloons. How many are Red Balloon and Yellow Balloon? 62-24=38 (only) 3/5 red =2/3 yellow 9 red = 10 yellow red: yellow = 10:9 38/( 10+9)=2 red: 2 *10.
There are 36 students reading in the school reading room, 4/9 of whom are female students. Later, several female students came. At this time, the number of female students accounted for 3/5 of the number of students. Later, several female students came. Original female student: 36×4/9= 16 (person)
Former male classmate: 36- 16=20 (person)
Total number of employees: 20( 1-3/5)= 50 (persons)
Female: 50×3/5=30 (person)
Number of female students: 30- 16= 14 (person)
7. When water turns into ice, its volume is110, 2. 16 cubic meters of ice melts into water, what is its volume? 2. 16/( 1+ 1/ 1 1)= 1.98(m3)
8. Party A's grain is 560 tons. If 2/9 of Party A's grain is shipped to Party B, Party A's grain is exactly the same. How many tons of grain does Party A have? How many tons of grain does B have? Now Party A and Party B each have 560 ÷ 2 = 280 tons, while Party A has 280 ÷ (1-2/9) = 360 tons, and Party B has 560-360 = 200 tons.
9. The price reduction of TV sets in 200 yuan is 2/ 1 1. What's the price of this TV set now? The original price is 200 ÷ 2/ 1 1 = 2200 yuan, and the current price is 2200-200 = 2000 yuan.
10。 Car A has traveled more than 2/5 kilometers from A to B.. At this time, there are still 70 kilometers from B. How many kilometers are there between A and B? The whole journey 1-2/5 = 3/5 is 20+70 = 90km, and the distance between Party A and Party B is 90 ÷ 3/5 = 150km.
1 1. Xiaoming reads books. On the first day, he read 28 pages. The next day, he read the whole book 1/5 (1). Last two days, * * * read 3/8 (8/3) of the whole book. How many pages does this book have? What I read on the first day accounts for 3/8- 1/5 = 7/40 of the whole book. This book has 28 pages: 7/40 =160.
12. Both the master and the apprentice are processing a batch of parts. After a period of processing, the master processed 84 parts. The apprentice made 63 parts. The master works more than the apprentice, accounting for 1/28 of all tasks. How many parts are there in this batch? Suppose there are x parts * * *1/28x = 84-631/28x =19x = 532, so there are 532 parts * * *.
13. A barrel of oil, after eating 7/ 10, added 15 kg. At this time, the oil in the barrel is exactly half of that in a barrel. How much does this barrel of oil weigh? 15 ÷ (7/10-1/2) = 75 (kg)
14. A train runs from Shanghai to Tianjin, accounting for 3/5 of the whole journey. If you drive at 106 km/h, you can reach Tianjin in five hours. How many kilometers is the railway from Shanghai to Tianjin? (106 * 5)/(1-(3/5)) = 530/0.4 =1325 (km)
15. There are 46 students in grade six who participate in math interest groups, among which 4/5 girls are 3/2 times as many as boys. How many boys and girls joined the interest group? The ratio of male to female students is 4/5: 3/2 = 8: 15. The number of boys is 46/(8+ 15)*8= 16. The number of girls is 46- 16=30.
16. It takes Zhang Hong five hours to copy a manuscript. This manuscript has been copied by others 1/3, and the rest was given to Zhang Hong. How many hours does it take to copy it? (1-1/3)/(1/5) =10/3 It takes 3 hours1/3 to complete the replication.
17. Two trains leave from two cities 600 kilometers apart at the same time. One train runs at 60 kilometers per hour, and the other train runs at 75 kilometers per hour. How many hours will the two trains meet? 600/(60+75)=40/9 (hours)
After 40/9 hours, the two cars can meet.
18. A motorcycle travels 64 kilometers per hour. It takes 3/4 hours to find this speed from a to b. What is the distance between a and b? 64× 3/4 = 48km
19. The fruit shop sold a batch of fruits in two days. On the first day, 3/5 of the total fruit weight was sold, 30 kilograms more than the next day. How many kilograms are there in this batch of fruit? If you sell 3/5 of the total fruit weight on the first day, you will sell 2/5, 3/5-2/5= 1/5 on the second day, and if you sell more on the first day than on the second day, you will sell 301/5 =150 kg. The formula is 65440.
20. Jessie Primary School has 9 10 students, seven quarters of whom are girls. How many are girls? How many boys are there? 910 * 4/7 = (910 * 4)/7 = 520 ... girls 9 10-520=390 ... boys.
2 1. A rectangular piece of land is 60 meters long and 2/5 wide. What is the area of this land? 4/5*5/8=(4*5)/(5*8)= 1/2 (m) 4/5-1/2 = 8/10-5/10 = 3.
22. The ratio of red goldfish to black goldfish in the goldfish pond is 7:3. There are 9 black goldfish. How many red goldfish are there? 9 ÷ 3× 7 = 2 1
Grade 23.6 students 132, in which the ratio of male to female students is 6: 5. How many boys and girls are there in the sixth grade? 132 ÷ (6+5) = 12 for male students 12× 6 = 72 for female students 12× 5 = 60.
24. The ratio of A to B is 2:3, and the ratio of B to C is 4:5. Find the ratio of a to c: a: b = 2: 3 = 8:12 b: c = 4: 5 =12:15 a: b: c.
25. The number of trees planted in Jiefang Road Primary School this year is 1.2 times that of last year. Write down the ratio between the number of trees planted in this primary school this year and the number of trees planted last year. Simplified .65,438+0.2: 65,438+0 = 6.5.
Last year, the ratio of the output of color TV sets to the total output of TV sets in a TV factory was 9/20. Last year, * * * produced 250,000 TV sets, including how many color TV sets? 250000× 9/20 =112500 sets.
27. Workers in a factory account for 2/3 of the total number of employees in the factory, technicians account for 2/9 of the total number of employees in the factory, and the rest are cadres. Write down the proportion of workers, technicians and cadres in this factory. Cadres account for 1-2/9 = 9/ 1 of the total number of employees in the factory. The ratio of workers, technicians and cadres in this factory is two-thirds.
28. The number of students in a class is between 40 and 50, and the ratio of boys to girls is 5:6. How many boys and girls are there in this class? Because the number is an integer, the class number can be divisible by 5+6 = 1 1, so the class number is 44, and the boys are 44 ÷ (5+6) × 5 = 20.
29. The ratio of science and technology books to literature and art books in the library is 4: 5. After purchasing 300 works of art, the ratio of science and technology books to literature and art books is 5: 7. What percentage of literature and art books have increased? Original literature and art books: 300 ÷ (7/12-5/9) =10800 (this book) increased by 300÷ 10800≈2.8%.
30.100g sugar water just fills a glass, including10g sugar. Pour out10g sugar water from the cup, and then fill the cup with water. What's the ratio of sugar to water in the quilt? It turns out that the water in it is 90 and the sugar is 10. Pour out10g, and there is still 90 in it, in which water 8 1, sugar 9 1 and sugar 9 are 9/9 1.
3 1. There are only 175 students in grades 5 and 6. Divide into three groups to participate in the activities. The ratio of the first group to the second group is 5: 4, and the third group has 67 people. How many people are there in the first and second groups? (1) The first and second groups have 175 -67 students (2) The first group has 108 students ×5/9=60 students (3) The second group has 108 students× 4 students.
32. There are 465 students in a school, of whom 2/3 are girls and 20 are less than 4/5 boys. How much is the male and female? Two thirds of the girls are less than four fifths of the boys. Girls are twenty (4/5)/(2/3)=6/5 less than boys. 20/(2/3)=30 boys have (465+30)/( 1+6/5)=225 girls have.
33. For a manuscript, 1 7 was typed on the first day, and 2/5 was typed on the second day. The next day was nine pages more than the first day. How many pages are there in this manuscript? 9 divided by (5' s 2-7 1)= 9 divided by 35' s 9 = 35 (pages) A: This manuscript has 35 pages.
34. On a piece of land, the aspect ratio is 8: 5, and the length is 24 meters more than the width. How many square meters is this land? If the length is 8 and the width is 5, it is more than 3, which is 24 meters.
Then one is: 24/3=8 meters.
That is, the length is 8 * 8 = 64m and the width is 8 * 5 = 40m.
Area: 64 * 40 = 2560m2.
35. If there are 25% more boys than girls, how many girls are less than boys? Girls 1, boys 1+25% = 125%. The number of girls is less than that of boys (125%-1) ÷125% = 20%.
36. This breeding factory has raised 65,438+0,987 pigs this year, which is three times less than that of last year, that is, 245 pigs. How many more pigs have been raised this year than last year? Raising pigs last year: (1987+245)/3=744 There are more pigs this year than last year: 1987-744= 1243.
37. The ratio of Xiao Wei and Xiaoying's donation to Project Hope is 2:5. Xiaoying donated 35 yuan. How much did Xiao Wei donate? Let Xiao Wei donate X yuan.
So 2:5=X:35: X= 14 yuan Xiaowei donated 14 yuan.
38. The three averages are all 8.4, of which the first number is 9.2, the second number is 0.8 less than the third number, and what is the third number? The third number is 8.4. Solution: Let the third number be x and the column equation be: 3*[9.2+(x-0.8)+x]=8.4. The solution is x=8.4.
39. There are two ropes. The length of the first rope is 1.5 times that of the second rope, and the second rope is 3 meters shorter than the first rope. How long are these two ropes? If the length of the second root is x meters, the length of the second root is1.5xm1.5x-x = 30.5x = 3x = 66x1.5 = 9 (meters), the first root is 6 meters, and the second root is 9 meters.
40. The construction team built a road, and the repaired length and the remaining ratio were 4: 5. If you build another 25 meters, it will just reach the midpoint of this road. What is the total length of this road? 4+5=9 solution: Let the total length of this road be x meters: (5/9-4/9) x = 251/9x = 25 x = 225, and the total length of this road is 225 meters.