Question

in a class of 40 pupils the no of girls is three-fifths of the no of boys find the boys in a class

Answer 1

no.of pupils=40
no.of boys=no.of pupils-no.of girls
                   =(1-3/5)of 40
                    =2/5 x 40                                               
                    =16 

Answer 2

let no. of boys= x
so no. of girls= 3/5x
A.T.Q.
x+3/5*x=40
(5x+3x)/5=40
8x/5= 40
x=(40*5)/8
x= 25