help please

Let the number of girls  = G

Then, the number of boys =  G + 124

So we have this

[ G + 124 ]/ G  =  11 / 9        cross-multiply

9 G + 1116 = 11G            subtract 9G from both sides

1116  =  2G                   divide both sides by 2

558  =  number of girls

And   558 + 124  = 682  =  number of boys

And     682 / 558  =  11/9

So....there are  682 + 558  =  1240  total students