In an examination, 40% of the students failed in English, 27% failed in Mathematics and 19% failed in both. What percentage of students passed in both subjects?

💡 Solution & Explanation

Students who failed in at least one subject = failed in English + failed in Mathematics − failed in both (they were counted twice) = 40 + 27 − 19 = 48%. So the students who passed in both = 100 − 48 = 52%. Forgetting to subtract the 19% who failed in both gives 33%, which is too low.