A school has a boy to girl ratio of 6:7.If there are 288 boys, how many girls are there?

Set up a proportion:

$${\frac{{\mathtt{6}}}{{\mathtt{7}}}} = {\frac{{\mathtt{288}}}{{\mathtt{x}}}}$$

Cross multiply:

$${\mathtt{6}}{\mathtt{\,\times\,}}{\mathtt{x}} = {\mathtt{2\,016}}$$

And simplify:

$${\mathtt{x}} = {\mathtt{336}}$$

Hope this helped!

:D

There would be 336 girls if my calculations are correct.