Two events AAA and BBB are such that P(A∣B)=12P(A|B) = \frac{1}{2}P(A∣B)=21, P(B∣A)=13P(B|A) = \frac{1}{3}P(B∣A)=31, and P(A∩Bc)=14P(A \cap B^c) = \frac{1}{4}P(A∩Bc)=41. What is P(B)P(B)P(B)?
1/4
1/3
1/2
2/3