AFCAT Model Paper 5

Given:
The difference between the number of boys and girls = 100
The percentage of boys is 40%
The number of boys in class B is 50% more than the number of boys in class A
The number of girls is thrice the number of boys
The total number of students in class C is twice then the total number of students in class A and Class B together
In class C boys and girls are in the ratio of 15 : 2
Calculation:
In class A, let the total number of girls be x
⇒x=(

100

20

)×60
⇒ x = 300
⇒ Girls - Boys = 100
⇒ Number of Boys = 300 - 100 = 200
In class B,
Number of Boys = 200 × (1 + 50%) = 300
Number of Girls = 300 × 3 = 900
In class C,
Total number of boys and girls = 2 × (300 + 200 + 900 + 300) = 2 × 1700 = 3400
Number of girls =(

2

17

)×3400=400
Total number of girls in A, B and C
⇒ 300 + 900 + 400 = 1600
∴ The total number of girls in all classes together is 1600.