Question

Задача В классе 36 человек. 50% от числа девочек - это 5/8(пять восьмых) от числа мальчиков. Найдите число девочек и число мальчиков. -------------------------- Мне нужно именно объяснение решения сией задачи, а не просто сухое решение

Answer 1

50 %  это 1/2
Пусть в классе x девочек тогда мальчиков 36-x
Теперь по условию задачи
x*1/2=(36-x)*5/8
x/2=22,5-5/8 x
x/2+5x/8=22,5
4x/8+5x/8=22,5
9x/8=22.5
9x=180
x=20 девочек в классе
36-20=16 мальчиков в классе

Answer 2

Problem Analysis

We are given that there are 36 students in a class, and that 50% of the number of girls is equal to 5/8 of the number of boys. We need to find the number of girls and the number of boys in the class.

Solution

Let's assume the number of girls in the class is G and the number of boys is B.

According to the given information, 50% of the number of girls is equal to 5/8 of the number of boys. Mathematically, this can be expressed as:

0.5G = (5/8)B

To solve this equation, we can multiply both sides by 8 to eliminate the fraction:

8 * 0.5G = 8 * (5/8)B

Simplifying, we get:

4G = 5B

Now, we know that the total number of students in the class is 36. So we can write another equation:

G + B = 36

We have a system of two equations with two variables. We can solve this system to find the values of G and B.

Let's solve the system of equations:

Equation 1: 4G = 5B

Equation 2: G + B = 36

To solve Equation 2 for G, we can subtract B from both sides:

G = 36 - B

Now we can substitute this value of G into Equation 1:

4(36 - B) = 5B

Expanding and simplifying:

144 - 4B = 5B

Adding 4B to both sides:

144 = 9B

Dividing both sides by 9:

B = 16

Now we can substitute this value of B back into Equation 2 to find G:

G + 16 = 36

Subtracting 16 from both sides:

G = 20

Therefore, there are 20 girls and 16 boys in the class.

Answer

The number of girls in the class is 20 and the number of boys is 16.