Question Detail
Question
In a class of 40 students, 32 are good in mathematics, 24 in physics, and 4 take neither. How many are good in both mathematics and physics?
Correct Answer
Option C is the correct answer.
Detailed Explanation
Students taking at least one = 40 − 4 = 36. Using inclusion-exclusion: 36 = 32 + 24 − x → x = 20.
Hint
Find those taking at least one, then apply inclusion-exclusion.