In a group of 15 people, 7 read French,8 read English while 3 of them read none of these two. How many of them read French and English both?
Q1. In a group of 15 people, 7 read French,8 read English while 3 of them read none of these two. How many of them read French and English both?
Answer: 3
Explanation: Using set theory: |F ∪ E| = 15 − 3 = 12 (those who read at least one). |F ∩ E| = |F|+|E| − |F∪E| = 7+8−12 = 3.