Edexcel S1 2017 October — Question 4

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2017
SessionOctober
TopicConditional Probability
TypeTree diagram with two-stage events

  1. The following incomplete tree diagram shows the relationships between the event \(A\) and the event \(B\).
    \includegraphics[max width=\textwidth, alt={}, center]{77ae01cd-2b58-48ab-889f-272e27ecf99d-14_799_839_351_548}
Given that \(\mathrm { P } ( B ) = \frac { 9 } { 20 }\)
  1. find \(\mathrm { P } ( A )\) and complete the tree diagram,
  2. find \(\mathrm { P } \left( A ^ { \prime } \mid B ^ { \prime } \right)\).