Find How Many Liked Product P3 Only
Question:
In a survey it was found that 21 persons liked product P1, 26 liked product P2 and 29 liked product P3. If 14 persons liked products P1 and P2; 12 persons liked products P3 and P1; 14 persons liked products P2 and P3 and 8 liked all the three products. Find how many liked product P3 only.
Solution
\[ \text{P3 only}=n(P3)-n(P3\cap P1)-n(P2\cap P3)+n(P1\cap P2\cap P3) \] \[ =29-12-14+8 \] \[ =11 \]Hence, 11 persons liked product P3 only.