Question

В классе девочек в 3 раза больше чем мальчиков. Если из этого класса уйдут 6 девочек и придут 3 мальчика, то девочек будет на 5 больше, чем мальчиков. Сколько учеников в данном классе?

Answer 1

Пусть  мальчиков х, тогда 3х девочек. 
Х + 3 + 5 = 3х - 6 
Х + 8 = 3х - 6
8 = 2х - 6
2х=14
х=7 мальчиков в классе
3*7 = 21 девочка в классе
21+7=28 учеников в классе
Ответ 28 учеников 

Answer 2

Problem Analysis

We are given the information that there are three times as many girls as boys in a class. If 6 girls leave the class and 3 boys join, the number of girls will be 5 more than the number of boys. We need to determine the total number of students in the class.

Solution

Let's assume the number of boys in the class is x. According to the given information, the number of girls in the class is three times the number of boys, which is 3x.

After 6 girls leave the class, the number of girls becomes 3x - 6. Similarly, after 3 boys join the class, the number of boys becomes x + 3.

According to the problem, the number of girls will be 5 more than the number of boys after these changes. Mathematically, we can represent this as:

(3x - 6) = (x + 3) + 5

Now, let's solve this equation to find the value of x.

Solving the Equation

Expanding the equation:

3x - 6 = x + 3 + 5

Combining like terms:

3x - 6 = x + 8

Subtracting x from both sides:

2x - 6 = 8

Adding 6 to both sides:

2x = 14

Dividing both sides by 2:

x = 7

So, the number of boys in the class is 7.

Finding the Total Number of Students

Now that we know the number of boys, we can find the number of girls by multiplying it by 3:

Number of girls = 3 * 7 = 21

The total number of students in the class is the sum of the number of boys and girls:

Total number of students = Number of boys + Number of girls = 7 + 21 = 28

Therefore, there are 28 students in the class.

Answer

There are 28 students in the given class.