Let the total number of people be x
To find the number of girls in the class we must first find the total number of people in the class
First find the total parts
2 + 5 = 7
2/7 of the total number of people are boys
So we have
2/7 × x = 40
Multiply through by 7
2x = 280
Divide both sides by 2
x = 140
There are 140 people in the school
Finding the number of girls we have
5/7 × 140
There are 100 girls in the school
Hope this helps you
The ratio of boys : girls is 2 : 5.
In other words, boys are 2 parts of the school while girls are 5 parts of the school.
Since there are 40 boys, 2 parts of the school is 40. Thus:
1 part is 20.
Since there are 5 parts girls, there are