IBPS Clerk Prelims Model Paper 17

Let A and B represent the sets of students who passed in English and Mathematics respectively.
If 15% of candidates failed in both, then 85% passed at least one of the exams.
Then, the total number of students passed in one or both subjects
= n (A ∪ B) = n (A) + n (B) - n (B ∩ B)
0.85 = 0.75 + 0.65 - n (A ∩ B)
n (A ∩ B) = 1.40 -0.85 - 0.55
55% of number of students = 495
∴ Number of students =

495

55

×100 = 900