Question

in a given classroom the number of girls is 10 greater than 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 students​

Answer 1

a) 35, b) 25, c) 60

Explanation:

The number of girls is 10 more than the number of boys, so it's a good thing to choose a variable to represent the number of boys.

Number of boys: b

Number of girls: b + 10

Ratio of girls:boys is 7:5, so

`(b+10)/(b)=(7)/(5)`

"Cross multiply" to get

`7b=5(b+10)\\7b=5b+50\\2b=50\\b=25`

There are 25 boys. There are 10 more girls, so the number of girls is 35, and the total number of students is 60.

That's a packed classroom!