[tex]30-girs\ trying\ out\\12-grils\ selected\\\\\frac{12}{30}=\frac{2}{5}-ratio\\\\40-boys\ trying\ out\\16-boys\ selected\\\\\frac{16}{40}=\frac{2}{5}\\\\When\ you\ are\ looking\ for\ ratio\ you\ need\ to\ divide\ this\ part\ which\\ratio\ you\ are\ looking\ for,\ by\ whole\ number.\ (example\ is\ higher)[/tex]