Question

В первом классе число девочек так относится к числу мальчиков как 6:7 .Сколько мальчиков останутся без пары ,если в классе 26 человек? 1)2 2)12 3)14 4)1 (пожалуйста помогите решить,за ранее спасибо))

Answer 1

Пускай одна часть х тонда мальчиков 6х девочек 7х уравнение
6х+7х=26
13х=26
х=26/13
х=2
мпльчиков-2*6=12
девочек- 2*7=14

Answer 2

Problem Analysis

In the given problem, the ratio of the number of girls to the number of boys in the first grade is given as 6:7. We need to find the number of boys who will be left without a partner if there are 26 students in the class.

Solution

To find the number of boys, we can use the given ratio. Let's assume the number of girls is 6x and the number of boys is 7x, where x is a constant.

According to the given information, the total number of students in the class is 26. So, we can write the equation:

6x + 7x = 26

Simplifying the equation:

13x = 26

Dividing both sides of the equation by 13:

x = 2

Now, we can find the number of boys by substituting the value of x back into the equation:

Number of boys = 7x = 7 * 2 = 14

Therefore, there will be 14 boys in the class.

To find the number of boys without a pair, we subtract the number of boys from the total number of students:

Number of boys without a pair = Total number of students - Number of boys = 26 - 14 = 12

Therefore, 12 boys will be left without a pair.

So, the correct answer is 2) 12.

Conclusion

In the first grade class with a ratio of 6:7 for girls to boys, if there are 26 students in total, there will be 14 boys and 12 boys will be left without a pair.