(a) 5/13
Given A and B are independent
P(A ∩ B) = P(A) + P(B)
⇒ Now P(A ∪ B) = P(A) + P(B) – P(A ∩ B)
(i.e.,) Now P(A ∪ B) = P(A) + P(B) – P(A).P(B)
0.6 = 0.35 + P(B) – (0.35) P(B)
⇒ P(B) = (1 – 0.35) = 0.6 – 0.35
0.65 P(B) = 0.25
∴ P(B) = 0.25/0.65 = 25/65 = 5/13