Question

in a class the ratio of boys to girls is 7.5 if the number of boys is 10 more than the number of girls find the number of boys in the class also find the total number of students​

Answer 1

Ratio of Boys :Girls= 7:5

let boys are 7x , girls are 5x

because boys are 10 more than girls,

means difference between boys and girls is 10

7x-5x = 10 ; 2x= 10; x= 5

so boys = 7x = 35

girls = 5x = 25

total = 35+25=60

Answer 2

ANSWER

Let the tens digit of the required number be x and the units digit be y. Then,

x+y=12 .........(1)

Required Number = (10x+y).

Number obtained on reversing the digits = (10y+x).

Therefore,

(10y+x)−(10x+y)=18

9y−9x=18

y−x=2 ..........(2)

On adding (1) and (2), we get,

2y=14⟹y=7

Therefore,

x=5

Hence, the required number is 57.