9/25 of the pupils in a school hall are girls. What percentage of the pupils in the school hall are boys?
To find the percentage of boys in the school hall, we subtract the percentage of girls (9/25) from 100% since the sum of the percentages of boys and girls must equal 100%.
100% - 9/25 = 2500/2500 - 225/2500
= 2275/2500
So, approximately 91% of the pupils in the school hall are boys.