Medium
In a class of 60 students, 35 like tea, 30 like coffee and 10 like both. How many students like neither tea nor coffee?
Explanation
Explanation
Step 1: Use the formula n(T ∪ C) = n(T) + n(C) − n(T ∩ C).
Step 2: n(T ∪ C) = 35 + 30 − 10 = 55 students like at least one drink.
Step 3: Students who like neither = total − n(T ∪ C) = 60 − 55 = 5.
Step 4: Venn check: only tea = 25, both = 10, only coffee = 20, and 25 + 10 + 20 = 55, so 5 are outside both circles ✓.
Answer: 5.
PRO TIP
Re-check your working by substituting the answer back into the original question.