Please I really need help I don't get it. I did a ratio of Boys:Girls but the I didn't know what to do. I have to do it in ratios so please solve in ratios, thank you so so so so so much!

Please I really need help I dont get it I did a ratio of BoysGirls but the I didnt know what to do I have to do it in ratios so please solve in ratios thank you class=