Question

the number of boys and girls in a class are in the ratio 7 and 5 the number of boys is 8 more than the number of girls what is the total class strength​

Answer 1

Let

Boys = b

Girls = g

The number of boys and girls in a class are in the ratio 7:5

b:g=7:5

b/g=7/5

b5=g7

b5/5=g7/5

b=g7/5...............(1)

the number of boys is 8 more than the number of girls

b=g+8.............(2)

Put the value of b from (1) to (2)

g7/5=g+8

5*(g7/5)=5*(g+8)

g7=5g+40

g7-g5=40

2g=40

2g/2=40/2

g=20

Put the value of g in (2)

b=20+8

b=28

Boys are 28 and Girls are 20

Answer 2

Answer:

48

Step-by-step explanation:

Let the number of boys be 7x and girls be 5x.

According to the question,

7x = 5x + 8

⇒ 7x – 5x = 8

⇒ 2x = 8

⇒ x = 8/2

⇒ x = 4

Therefore, Number of boys = 7×4 = 28

And, Number of girls = 5×4 = 20

Total number of students = 20+28 = 48