(d) Clearly, $P(A \cup B \cup C) = 1$ $\Rightarrow \ P(A) + P(B) + P(C) = 1$ $\Rightarrow P(A) + \frac{1}{2}P(A) + \frac{1}{3}P(A) = 1$ $\Rightarrow \ \frac{11}{6}P(A) = 1$ $\Rightarrow P(A) = \frac{6}{11}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.