A. 3/5 of the class are girls. B. 96 of the pupils are boys.
A. To find this answer you subtract 2 from 5 to get 3 (numerator or top of fraction) then use 5 as the denominator or bottom of the fraction.
B. To find this answer, you divide 240 by 5, to show how many pupils are in 1/5 of the class (48). Then multiply 48 by 2, to get the 2/5 of the pupils who are boys (96).