Question

At a school the number of boys: number of girls = 11 : 9

there are 124 more boys than girls

work out the total number of students at the school

Answer 1

b = boys

g = girls

`b:g=11:9, b=g+124`

`b=11g/9`

Insert in the second equation

`11g/9=g+124`

Solve for g

`11g=9g+124\cdot9`

`2g=124\cdot9\implies g=62\cdot9=\boxed{558}`

Solve for b

`b=g+124=\boxed{682}`

Hope this helps.