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In another tree planting activity, the total index of the two groups is the same, which is more than 100 trees. It is known that the number of people in the two groups is different. In the first group, one person planted 5 trees and the others planted 13 trees; in the second group, one person planted 4 trees and the others planted 10 trees. How many people are there in the two groups? Arithmetic and equation are OK. Please make it clear to me I want formula, formula
The number of trees in the two groups is equal,
According to the meaning of the title,
The number of trees, divided by 13, leaves 5; divided by 10, leaves 4;
Using the solution of Chinese remainder theorem:
1) The smallest fraction that can be divided by 13 and divided by 10 and 4 is: 13 × 8 = 104
2) The smallest fraction that can be divided by 10 and divided by 13 and 5 is: 10 × 7 = 70
104+70=174
The number that satisfies the condition of more than one hundred is only 174
So there are 174 trees in each group
One group has: (174-5) △ 13 + 1 = 14 people
The two groups were (174-4) △ 10 + 1 = 18
Two groups: 14 + 18 = 32
If we use an equation, it's an indefinite equation combined with an inequality
Let X and y be positive integers
200>13(x-1)+5>100
200>10(y-1)+4>100
208>13x>108
206>10y>106
16> X > 8 and 4 / 13
20.6>y>10.6
13(x-1)+5=10(y-1)+4
13x-13+5=10y-10+4
13x-10y=2
y=(13x-2)/10
13x-2 is divisible by 10
Then the single digit of X can only be 4
So x = 14
y=（13*14-2)/10=18
X + y = 14 + 18 = 32 people
A: there are 32 people in the two groups
In the spring tree planting activities, 150 trees were planted in the fourth grade, and half of the total trees planted in the fourth and fifth grade were planted in the sixth grade,
Sixth grade tree planting [150 + 150 * (1 + 1 / 5)] * 1 / 2 = 165
Class 6 (1) participated in the tree planting activities. Three boys and five girls planted one tree. There were 100 students in the whole grade. A total of 30 trees were planted. How many boys and girls were involved in the activities?
Suppose there are x boys and 100-x girls, then there are 13X trees for boys and 15 (100-x) trees for girls. According to the meaning of the question, we can get the equation: 13X + 15 (100-x) = 30, & nbsp; 5x + 3 (100-x) = 450, & nbsp; & nbsp; & nbsp; & nbsp; 5x + 300-3x = 450, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 2x = 150, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; &X = 75, so there are 100-75 girls = 25. A: there are 75 boys and 25 girls
It takes 7.5 hours for a middle school to plant trees outside the school. It takes 5 hours for the eighth grade students to plant trees alone. Now let the seventh and eighth grade students plant trees together for one hour, and then let the eighth grade students complete the rest. How many hours do it take?
Suppose that it takes x hours to complete, from the meaning of the question, 17.5 + 15x = 1, the solution is: x = 413
RELATED INFORMATIONS
- 1. If the seventh grade students are allowed to do it alone, it will take 7.5 hours to complete. If the eighth grade students are allowed to do it alone, it will take five hours How much time does it take to finish the rest of the work if the seventh and eighth grade work together for one hour, and then the eighth grade finish the rest of the work alone? (solve the equation with one variable once)
- 2. The sixth grade students took part in the tree planting activities. 42 students planted 104 trees. The average boy planted 3 trees and the girl planted 2 trees. How many boys and girls are there?
- 3. In the tree planting activities, each student in Grade 6 plants 8.5 trees on average. If men and women are calculated separately, then boys plant 10 trees on average and girls plant 6 trees on average. What percentage of the total number of girls in this grade? fast
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- 5. There was a child who bought coke and had three empty bottles to exchange for one. The child bought 10 bottles and asked him how many bottles he could drink?
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- 9. Buy a bottle of shampoo 30 yuan to buy 5 Ping free 1 bottle to buy 8 bottles to buy 2 bottles, my mother and colleagues to buy 12 bottles, how to buy cost-effective?
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- 11. The school has organized tree planting activities. It is known that there are 23 people planting trees in place a and 17 people planting trees in place B. now 20 people are transferred to support, so that the number of people planting trees in place a is more than twice that of place B. how many people should be transferred to place a and place B?
- 12. The school has organized tree planting activities. It is known that there are 23 people planting trees in place a and 17 people planting trees in place B. now 20 people are transferred to support, so that the number of people planting trees in place a is more than twice that of place B. how many people should be transferred to place a and place B?
- 13. The students took part in the tree planting activities. There were 8 students in the first group, with an average of 5 trees per person. There were 6 students in the second group, with a total of 44 trees. How many trees did each student plant in the second group?
- 14. On tree planting day, boys plant 80 more trees than girls. On tree planting day, boys plant 60%. How many trees do boys and girls plant
- 15. On the tree planting day, each student of a class plants 6 trees on average. If it is done by girls alone, each student should plant 15 trees, then it is done by boys alone, and each student should plant () A. 9 trees B. 10 trees C. 12 trees D. 14 trees
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- 17. A class is going to plant trees on tree planting day If each student plants 14 saplings, the remaining 20 saplings will not be planted. If each student plants 15 saplings, an additional 11 saplings will be prepared. How many students are there in this class?
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