Question

In a given class room, the number of girls is ten greater than the number of boys. If the ratio of the number of girls to the number of boys is 7:5 then find A. the number of girls B. the number of boys C. the total number of student

Answer 1

Given,
Ratio of Girls:Boys (G:B) = 7:5
Also, number of girls = 10 + number of boys
G = 10 + B

G/B = 7/5
(10+B)/B = 7/5
50 + 5 B = 7B
2B = 50
B = 25
G = 10 + B = 35..
A. Number of girls = 35
B. Number of boys = 25
C. Total students = 60

OR
Given G:B = 7:5
Difference between number of girls and boys = 10
Ratio difference = 2 parts (7-5=2)
2 parts===10
1 part ===5
7 parts(gilrs) == 7*5 = 35
5 parts (boys) == 5*5 =25
12 parts(total) = 5*12 = 60.

Hope it helps