The events A A\,A and B B\,B are such that P(A)=320P(A) = \dfrac{3}{20}P(A)=203, P(A∩B)=120P(A \cap B) = \dfrac{1}{20}P(A∩B)=201 and P(A∣B)=514P(A \mid B) = \dfrac{5}{14}P(A∣B)=145.
Find P(B)P(B)P(B).
Find P(B∣A′)P(B \mid A')P(B∣A′).
164 exam-style questions on AQA A Level Maths 2.3.2 Conditional probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.