Question Detail
Question
In a class of 34 students, 24 are good in English while 15 are good in Mathematics. How many of them are good in both subjects?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Using inclusion-exclusion: n(E∪M) = n(E) + n(M) - n(E∩M). The total students is 34, which is n(E∪M) (assuming all students are good in at least one). So 34 = 24 + 15 - n(E∩M) → 34 = 39 - n(E∩M) → n(E∩M) = 5.
Hint
Use the principle of inclusion-exclusion for sets.