Let H and E be the sets of students passing in Hindi and English, respectively. Suppose the number of students be 100. Number of students passing in both the subjects =n(H∩E) =100−n(H∪E)
=100−[n(H)+n(E)−n(H∩E)]
=100−(35+45−20) =100−60 =40 Thus, the percentage of students passing in both the subjects is 40%