Question

The ratio between the number of girls to boys is 9:7.if there are 42

More girls than the number of boy's find the number of girls and boys

Answer 1

Let X be the number of boys.,

Given there are 42 more girls than boys.

So,number of girls=X+42.

Given,ratio of number of girls to boys is 9:7

ie, ((X+42)/X)=9/7

Cross multiplying them ,
7(X+42)=9X
​​​​​​opening bracket,

7X+(7*42)=9X
(7*42)=(9X-7X)
2X=294
X=(294/2)
X=147
ie, there are 147 boys are there.
So number of girls=147+42=189 girls.