Question

The number of boys and girls in a class are in the ratio 4 : 7. There are 15 more girls than boys. find the number of total students in the class

Answer 1

Answer:

The number of total students in the class is 55

Step-by-step explanation:

We will use the ratio method to solve the question

∵ The number of boys and girls in a class are in the ratio 4: 7

∵ There are 15 more girls than boys

→ That means the difference between them is 15

∵ The difference between the terms of their ratio = 7 - 4 = 3

→ By using the ratio method

→  boy  :  girl  :  difference

→  4      :  7      :  3

→  x      :  y      :  15

→ By using cross multiplication

∵ x × 3 = 4 × 15

∴ 3x = 60

→ Divide both sides by 3

∴ x = 20

∵ y × 3 = 7 × 15

∴ 3y = 105

→ Divide both sides by 3

∴ y = 35

∵ x represents the number of boys

∴ The number of boys is 20

∵ y represents the number of girls

∴ The number of girls is 35

∴ The total number of students = 20 + 35 = 55

∴ The number of total students in the class is 55