In an examination, 30% of total students failed in Hindi, 42% failed in English and 28% in both. The percentage of these who passed in both the subjects is :	Choose the correct choice from the following answers:
A) 23 B) 37 C) 56 D) 40 E) 81
Explanation:   Formula n(aâˆªb) = n(a) + n(b) âˆ’ n(aâˆ©b)   Fail in Hindi or English = 30 + 42 â€“ 28 = 44   Therefore students who passed = 100 â€“ 44 = 56.   Answer: 56
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In an examination, 30% of total students failed in Hindi, 42% failed in English and 28% in both. The percentage of these who passed in both the subjects is :