Question

The number of boys and girls in a class are in the ratio 7 is to 5 the number of boys is 8 more than the number of girls what is the total class strengthth

Answer 1

Given the ratio between the number of boys and girls in a class is 7 : 5

let the number of boys and girls be 7x and 5x respectively.

ATQ, the number of boys in the class is 8 more than the number of girls.

➡ no. if girls + 8 = no. of boys

➡ 5x + 8 = 7x

➡ 5x - 7x = -8

➡ -2x = -8

➡ x = -8/-2 = 4

therefore,

• no of girls = 5x = 5 × 4 = 20

• no. of boys = 7x = 7 × 4 = 28

hence, the total strength of the class = no. of girls + no. of boys

= 20 + 28

= 48 students

Answer 2

Answer:

Let the number of girls = x

Number of boys = x + 8

According to the problem given,

Ratio of boys and girls = 7 : 5

( x + 8 ) : x = 7 : 5

Product of the means = product of

the extremes

x * 7 = ( x + 8 ) * 5

7x = 5x + 40

7x - 5x = 40

2x = 40

x = 40 /2

x = 20

Therefore ,

Number of girls = x = 20

Number of boys = x + 8 = 20 + 8 = 28

Total students = number of girls +

number of boys

= 20 + 28 = 48