Question

После уроков ребята устроили генеральную уборку. 5 мальчиков и7 давочек вымыли все письменные столы в классе.Каждый из ребят вымыл одинаковое кол-во столов,но девочки вымыли на 4 стола больше. Сколько всего столов в классе?

Answer 1

5+7=12

5*2=10

7*2=14

14-10=4

12*2=24

Answer 2

Problem Analysis

We are given that 5 boys and 7 girls cleaned all the writing desks in the classroom. Each child cleaned an equal number of desks, but the girls cleaned 4 more desks than the boys. We need to determine the total number of desks in the classroom.

Solution

Let's assume that each child cleaned x desks. Since there are 5 boys and 7 girls, the total number of desks cleaned by the boys is 5x, and the total number of desks cleaned by the girls is 7x. According to the problem, the girls cleaned 4 more desks than the boys, so we can write the equation:

7x = 5x + 4

To solve this equation, we can subtract 5x from both sides:

7x - 5x = 5x - 5x + 4

2x = 4

Finally, we can divide both sides by 2 to find the value of x:

2x/2 = 4/2

x = 2

Therefore, each child cleaned 2 desks. To find the total number of desks in the classroom, we can multiply the number of desks cleaned by each child by the total number of children:

Total number of desks = (5 boys + 7 girls) * 2 desks/child

Total number of desks = 12 * 2

Total number of desks = 24

So, there are a total of 24 desks in the classroom.

Answer

The total number of desks in the classroom is 24.