Question

7. There are m boys and n girls in a class. If total number of boys in the class
is 24 and the ratio of number of boys to the total number of students in
the class is 4:7, then find the number of girls in the class.
(A) 15
(B) 18
(C) 14
(D) 28
​

Answer 1

Answer:

$4x = 24 \\ \\ x = 6$

Number of girls=3×6= 18

B) 18 ✔

Answer 2

let number of boys and total number of students be 4x and 7x
According to question
number of boys = 4x = 24
x = 24/4
x = 6
then total number of students = 7×6 = 42
Number of girls = total number of students - number of boys
= 42 - 24
= 18
Hence option B is the correct answer