In a class of 60 students, the number of boys and girls participating in the annual sports is in the ratio 3 : 2 respectively. The number of girls not participating in the sports is 5 more than the number of boys not participating in the sports. If the number of boys participating in the sports is 15, then how many girls are there in the class?

In a class of 60 students, the number of boys and girls participating in the annual sports is in the ratio 3 : 2 respectively. The number of girls not participating in the sports is 5 more than the number of boys not participating in the sports. If the number of boys participating in the sports is 15, then how many girls are there in the class? Correct Answer 30

Given:

Total number of students in the class = 60

The ratio of number of boys and girls participating in the annual sports = 3 : 2

The number of girls not participating in the sports is 5 more than the number of boys not participating in the sports

The number of boys participating in the sports = 15

Concept:

At first, finding the number of girls and boys participating in the annual sports. Then subtracting from total number of students to get the number of boys and girls not participating in the annual sports.

Calculation:

Let the number of boys and girls participating in the annual sports be 3x and 2x respectively

And the number of boys and girls not participating in the annual sports be y and (y + 5) respectively

The number of boys participating in the sports = 15

⇒ 3x = 15

⇒ x = 5

The number of girls participating in annual sports = 2x

⇒ 2 × 5 = 10

∴ The total number of students participating in annual sports = 15 + 10 = 25

Now, Total number of students in the class = 60

⇒ 25 + y + (y + 5) = 60

⇒ 2y + 30 = 60

⇒ 2y = 30

⇒ y = 15

The number of girls not participating in annual sports = y + 5 

⇒ 15 + 5 = 20

∴ Total number of girls = The number of girls participating in annual sports + The number of girls not participating in annual sports

⇒ 10 + 20 = 30

∴ Total number of girls in the class = 30

Related Questions

Each question below is followed by two statements I and II. You have to determine whether the data given in the statements are sufficient for answering the question. You should use the data and your knowledge of Mathematics to choose the best possible answer. What is the average weight of new students added? I. In a class 60% students are male and there average weight is 15 kg more than the female students, 9 males and 6 new female students joined the class and the average weight of the class increased by 0.84 II. Total male students in the class is 12 more than female students adding 9 male students to the class increases the average weight of male students by 1 kg and adding 6 female students increases the average weight of female students by 0.6.