Question

В пятых классах школы 80 человек.Из них отличники составляют 21.25%.В шестых классах 90 человек .Отличники составляют 20%.В каких классах больше отличников и на сколько человек? Пропорцией!СРОЧНО!!!ПРОПОРЦИЕЙ!!1

Answer 1

80чел. - 100%
х чел.  - 21, 25%
х=80*21,25/100=17 чел.

90чел. - 100%
х чел.  -  20%
х=90*20/100=18 чел. В 6-х классах на 1 отличника больше.

Answer 2

Analysis:

To determine in which grade there are more excellent students and by how many people, we need to compare the number of excellent students in the fifth and sixth grades.

Let's calculate the number of excellent students in each grade using the given percentages and total number of students:

In the fifth grade: - Total number of students: 80 - Percentage of excellent students: 21.25%

To find the number of excellent students in the fifth grade, we can use the following proportion:

x / 80 = 21.25 / 100

Simplifying the proportion:

x / 80 = 0.2125

Cross-multiplying:

x = 80 * 0.2125

Calculating:

x = 17

Therefore, there are 17 excellent students in the fifth grade.

In the sixth grade: - Total number of students: 90 - Percentage of excellent students: 20%

Using the same method, we can calculate the number of excellent students in the sixth grade:

y / 90 = 20 / 100

Simplifying the proportion:

y / 90 = 0.20

Cross-multiplying:

y = 90 * 0.20

Calculating:

y = 18

Therefore, there are 18 excellent students in the sixth grade.

Conclusion:

Comparing the number of excellent students in the fifth and sixth grades, we find that there are more excellent students in the sixth grade by 1 person. In the sixth grade, there are 18 excellent students, while in the fifth grade, there are 17 excellent students.