From given data No of students failed in hindi n(H) = 30% No of students failed in English n (E) = 25% No of students failed in both n(H ∩ E) = 10% ⇒ Percentage of students who failed n(H U E) = n(H) + n(E) – n(H ∩ E) ⇒ n(H U E) = 30 + 25 - 10 ⇒ n(H U E) = 45 Percentage of students who passed = 100 - (Percentage of students who failed) = 100 - 45 = 55%