Question 11
SetsA bookseller sells Mathematics and English books. If 30 customers buy Mathematics books, 20 customers buy English books and 10 customers buy the two books, how many customers has he altogether?
- A.30
- B.40
- C.50
- D.60
Show the answer and explanation
Answer: B (40)
Explanation
Total = 30 + 20 − 10 = 40 (the 10 who bought both were counted twice).