Q60 / 155 · WBJEE 2021 · Mathematics
Let $A, B, C$ be three non-void subsets of set $S$. Let $(A \cap C) \cup\left(B \cap C^{\prime}\right)=\phi$ where $C^{\prime}$ denote the complement of set $C$ in S. Then
- Correct answerA$A \cap B=\phi$
- B$A \cap B \neq \phi$
- C$\mathrm{A} \cap \mathrm{C}=\mathrm{A}$
- D$\mathrm{A} \cup \mathrm{C}=\mathrm{A}$
Solution
$(A \cap C) \cup\left(B \cap C^{\prime}\right)=\phi$
$\Rightarrow A \cap C=\phi$ and $B \cap C^{\prime}=\phi$ ...(i)
$\Rightarrow \mathrm{B} \subseteq \mathrm{C}$ ...(ii)
from (i) and (ii)
$A \cap B=\phi$
Hence, the correct answer is option: 'A'.